03-05-2006, 12:08 PM
BIOCHEM_DNA
Q: At which end of the tRNA is the aa bound?
A: The amino acid is covalently bound to the 3' end of the tRNA.
Q: Can RNA polymerase initiate chains?
A: Yes.
Q: Define transition.
A: Substituting purine for purine or pyrimidine for pyrimidine.
Q: Define transversion.
A: Substituting purine for pyrimidine or vice versa.
Q: Define tRNA wobble.
A: Accurate base pairing is required only in the first 2 nucleotide positions of an mRNA codon, so codons differing in the
A: 3rd 'wobble' position may code for the same tRNA/amino acid.
Q: Describe DNA replication.
A: Origin of replication: continuous DNA synthesis on leading strand and discontinuous (Okazaki fragments) on lagging strand.
A: Primase makes an RNA primer on which DNA polymerase can initiate replication.
Q: Describe DNA replication continued
A: DNA polymerase reaches primer of preceding fragment; 5' to 3' exonuclease activity of DNA polymerase I degrades RNA primer;
A: DNA ligase seals; 3' to 5' exonuclease activity of DNA polymerase 'proofreads' each added nucleotide.
Q: Describe topoisomerase activity
A: DNA topoisomerases create a nick in the helix to relieve supercoils
Q: Describe Euchromatin
A: Less condensed (vs. Heterochromatin), transcriptionally active
Q: Describe Heterochromatin
A: Condensed, transcriptionally inactive
Q: Describe key structural differences between nucleotides.
A: 1) Purines (A,G) have 2 rings.
A: 2) Pyrimidines (C,T,U) have 1 ring
A: 3) Guanine has a ketone.
A: 4) Thymine has a methyl
Q: Describe single-strand, excision repair.
A: Excision repair-specific glycosylase recognizes and removes damaged base.
A: Endonuclease makes a break several bases to the 5' side.
A: Exonuclease removes short stretch of nucleotides.
A: DNA polymerase fills gap.
A: DNA ligase seals.
Q: Describe the difference between Eukaryotic Vs. Bacterial, viral and plasmid origin of replications
A: Eukaryotic genome has multiple origins of replication.
A: Bacteria, viruses and plasmids have only one origin of replication.
Q: Describe the main difference in eukaryotic and prokaryotic synthesis of RNA.
A: Eukaryotes have 3 different RNA polymerases ('I, II, III synthesize RMT')
A: and prokaryotes have 1 RNA polymerase (which makes all 3 kinds of RNA).
Q: Describe the method by which introns are removed from primary mRNA transcript.
A: Introns are precisely spliced out of primary mRNA transcripts.
A: A lariat-shaped intermediate is formed.
A: Small nuclear ribonucleoprotein particles (snRNP) facilitate splicing by binding to primary mRNA transcripts and forming spliceosomes.
Q: Describe the number of bonds per purine-pyrimidine pair. Which is stronger?
A: G-C bond (3 H-bonds)
A: A-T bond (2 H-bonds
A: G-C bond is stronger
Q: Describe the structure of Chromatin.
A: Condensed by (-) charged DNA looped around (+) charged histones (nucleosome bead).
A: H1 ties the nucleosome together in a string (30 nm fiber)
Q: Describe tRNA structure.
A: 75-90 nucleotides, cloverleaf form, anticodon end is opposite 3' aminoacyl end.
A: All tRNAs both eukaryotic and prokaryotic, have CCA at 3' end along with a high percentage of chemically modified bases.
A: The amino acid is covalently bound to the 3' end of the tRNA.
Q: Does RNA polymerase have a proof reading function?
A: No.
Q: How do purines and pyrimidines interact, molecularly?
A: Purines and pyrimidines pair (A-T, G-C) via H-bonds
Q: How does RNA polymerase II open DNA?
A: RNA polymerase II opens DNA at promoter site
A: (A-T rich upstream sequence- TATA and CAAT)
Q: How is the original RNA transcript processed in eukaryotes? (3)
A: 1) Capping on 5' end (7-methyl G)
A: 2)Polyadenylation on 3' end ( =200 As)
A: 3) Splicing out of introns
Q: In eukaryotes, what must occur before an newly synthesized RNA transcript leaves the nucleus?
A: Only processed RNA is transported out the nucleus of eukaryotes.
Q: Name 3 types of RNA
A: 1) mRNA
A: 2) rRNA
A: 3) tRNA
Q: Name the charged histones around which (-) charged DNA loops (nucleosome core).
A: H2A, H2B, H3, H4 histones
Q: Name the enzyme responsible for the synthesis of RNA in prokaryotes.
A: RNA polymerase
Q: Name the enzymes involved in ss-DNA repair. (5)
A: 1) specific glycosylase.
A: 2) endonuclease.
A: 3) exonuclease.
A: 4) Dan polymerase.
A: 5) DNA ligase.
Q: Name the enzymes responsible for the synthesis of eukaryotic RNA.
A: RNA polymerase I
A: RNA polymerase II
A: RNA polymerase III
Q: What are exons?
A: Exons contain the actual genetic information coding for a protein
Q: What are four types of mutations that can occur in DNA?
A: 1) Silent
A: 2) Missense
A: 3) Nonsense
A: 4) Frame shift
Q: What are introns?
A: Introns are intervening noncoding segments of DNA
Q: What are the four features of the Genetic Code?
A: 1) Unambiguous
A: 2) Degenerate
A: 3) Commaless, non-overlapping
A: 4)Universal
Q: What atoms link aa in a protein chain?
A: Amino acids are linked N to C
Q: What changes occur in DNA structure during mitosis?
A: In mitosis, DNA condenses to form mitotic chromosomes
Q: What codon sequence is found at the 3' end of all tRNAs?
A: All tRNAs, both eukaryotic and prokaryotic, have CCA at 3' end.
Q: What direction is DNA synthesized in?
A: 5' > 3'.
A: Remember that the 5' of the incoming nucleotide bears the triphosphate (energy source for the bond).
A: The 3' hydroxyl of the nascent chain is the target.
Q: What direction is protein synthesized in?
A: Protein synthesis also proceed in the 5' to 3' (5' > 3')
Q: What direction is RNA synthesized in?
A: 5' > 3'.
A: Remember that the 5' of the incoming nucleotide bears the triphosphate (energy source for the bond).
A: The 3' hydroxyl of the nascent chain is the target.
Q: What does the AUG mRNA sequence code for?
A: AUG codes for methionin, which may be removed before translation is completed. In prokaryotes the initial AUG codes for a formyl-methionin (f-met).
Q: What does the P in P-site stand for?
Q: What does the A in A-site stand for?
A: P-site: peptidyl;
A: A-site: aminoacyl;
Q: What does the statement, 'the genetic code is commaless' mean?
Q: What is the exception to this rule?
A: The code is non-overlapping.
A: The exception are some viruses
Q: What does the statement, 'the genetic code is degenerate' mean?
A: More than one codon may code for the same amino acid
Q: What does the statement, 'the genetic code is unambiguous' mean?
A: Each codon specifies only one amino acid
Q: What does the statement, 'the genetic code is universal' mean?
Q: What are the exceptions (4)?
A: The same code is used in all lifeforms.
A: The exceptions are 1. mitochondria, 2. archaeobacteria, 3. Mycoplasma, 4. some yeasts
Q: What enzyme is responsible for 'charging' tRNA? How does it work?
A: Aminoacyl-tRNA synthetase.
A: This enzyme (one per aa, uses ATP) scrutinizes aa before and after it binds to tRNA.
A: If incorrect, bond is hydrolyzed by synthetase. The aa-tRNA bond has energy for formation of peptide bond.
Q: What inhibits RNA polymerase II?
A: alpha-amanitin inhibits RNA polymerase II
Q: What is a conservative missense mutation?
A: Mutation results in a different aa encoded, but that new aa is similar in chemical structure to the original code
Q: What is a frameshift mutation? What is usually the effect on the encoded protein?
A: A change in DNA resulting in misreading of all nucleotides downstream.
A: Usually results in a truncated protein.
Q: What is a missense mutation?
A: Mutation results in a different aa encoded.
Q: What is a nonsense mutation?
A: A change in DNA resulting in an early stop codon.
Q: What is a promoter?
A: Site where RNA polymerase and multiple other transcription factors bind to DNA upstream from gene locus.
Q: What is a silent mutation? What usually causes a silent mutation?
A: Mutation results in the same aa encoded. Often the base change is in the 3rd position of the codon
Q: What is a snRNP? What is its function?
A: snRNP = small nuclear ribonucleoprotein.
A: snRNPs facilitate splicing by binding to primary mRNA transcripts and forming spliceosomes.
Q: What is an enhancer?
A: Stretch of Dan that alters gene expression by binding transcription facts. May be located close to, far from, or even within (an intron) the gene whose expression it regulates.
Q: What is an Okazaki fragment?
A: The discontinuous DNA synthesized on the lagging strand during DNA replication
Q: What is hnRNA?
A: hnRNA = heterogeneous nuclear RNA
A: The initial RNA transcript is called hnRNA
Q: What is responsible for the accuracy of amino acid selection during peptide synthesis?
A: Aminoacyl-tRNA synthetase and binding of charged tRNA to the codon are responsible for accuracy of amino acid selection.
Q: What is the broad classification of nucleotides? (2)
A: Purines (A, G) and Pyrimidines (C, T, U)
Q: What is the difference between hnRNA and mRNA?
A: hnRNA = the initial RNA transcript
A: mRNA = capped and tailed transcript
Q: What is the difference between thymine and uracil?
A: Uracil found in RNA
A: Thymine found in DNA
Q: What is the function of DNA ligase during DNA Replication?
A: DNA ligase seals synthesized DNA into a continuous strand
Q: What is the function of DNA polymerase during DNA Replication? (2)
A: 5' to 3' exonuclease activity of DNA polymerase I degrades RNA primer;
A: 3' to 5' exonuclease activity of DNA polymerase 'proofreads' each added nucleotide.
Q: What is the function of DNA topoisomerase during DNA Replication?
A: DNA topoisomerases create a nick in the helix to relieve supercoils
Q: What is the function of primase in DNA Replication?
A: Primase makes an RNA primer on which DNA polymerase can initiate replication.
Q: What is the function of RNA polymerase I?
A: RNA polymerase I makes rRNA
Q: What is the function of RNA polymerase II?
A: RNA polymerase II makes mRNA
Q: What is the function of RNA polymerase III?
A: RNA polymerase III makes tRNA
Q: What is the mRNA initiation codon?
A: AUG, or rarely GUG
Q: What is the mRNA stop codons? (3)
A: UGA (U Go Away)
A: UAA (U Are Away)
A: UAG (U Are Gone)
Q: What is the result of 'mischarged' tRNA?
A: A mischarged tRNA (bound to wrong aa) reads usual codon but inserts wrong amino acid.
Q: What is the role of endonuclease in ss-DNA repair?
A: Endonuclease makes a break several bases to the 5' side.
Q: What is the role of excision repair-specific glycosylase in ss-DNA repair
A: Recognizes and removes damaged base.
Q: What is the role of exonuclease in ss-DNA repair?
A: Exonuclease removes short stretch of nucleotides.
Q: What prevents an incorrect aa-tRNA pairing?
A: If incorrect, the aa-tRNA bond is hydrolyzed by aminoacyl-tRNA synthetase.
Q: What role does histone H1 play in chromatin structure?
A: H1 ties the nucleosome together in a string (30nm fiber)
Q: What supplies the energy for formation of peptide bond?
A: The aa-tRNA bond has energy for formation of peptide bond.
Q: What would most likely be the result of a mutation of the promoter sequence?
A: Promoter mutation commonly results in dramatic decrease in amount of gene transcribed.
Q: When is ATP used in protein synthesis? When is GTP used in protein synthesis?
A: ATP is used in tRNA charging,
A: whereas GTP is used in binding of tRNA ribosome and for translocations.
Q: When is recombination involved in DNA repair?
A: If both strands are damaged, repair may proceed via recombination with undamaged homologous chromosome.
Q: Where does RNA processing occur in eukaryotes?
A: RNA processing occurs in the nucleus.
Q: Which is the largest type of RNA?
A: mRNA (massive)
Q: Which is the most abundant type of RNA?
A: rRNA (rampant)
Q: Which is the smallest type of RNA?
A: tRNA (tiny)
Q: Which nucleotide position in the codon has room for 'wobble'?
A: Codons differing in the 3rd 'wobble' position may code for the same tRNA/amino acid
BIOCHEM_GENETICS
Q: Von Geirke's disease is a result of?
A: Glucose-6-phosphatase deficiency; also known as Type I Glycogen Storage disease
Q: A build up of sphingomyelin and cholesterol in reticuloendothelial and parenchymal cells and tissues is found in what disease
A: Niemann-Pick disease
Q: A child is born with multiple fractures and blue sclera what is the diagnosis
A: Osteogenesis imperfecta;disease of abnormal collagen synthesis resulting in fractures and translucent Conn tiss over chorioid causing the blue sclera
Q: A congenital deficiency of tyrosinase would lead to
A: Albinism, can't synthesize melanin from tyrosine
Q: A patient presents with cataracts, hepatosplenomegaly, and mental retardation, what is the Dx?
A: Galactosemia
Q: A patient presents with corneal clouding and mental retardation that is, based on family history, inherited in an Autsomal recessive pattern, you impress your intern with a Dx of
A: Hurler's syndrome
Q: A patient presents with
A: 1. Hyperextensible skin
A: 2. Tendency to bleed
A: 3.Hypermobile joints
A: you astutely Dx them with
A: Ehlers-Danlos syndrome
Q: Absence of Galactosylceramide Beta-galactosidase leads to thebuild up of what compound in what disease
A: accumulation of galactocerebroside in the brain; Krabbe's disease
Q: Absence of hexosaminidase A results in the acumulation of what molecule that is characteristic of what disease
A: GM2-ganglioside accumulation; Tay-Sachs disease
Q: albinism increase risk of developing what
A: skin cancer
Q: Autosomal dominant defects will effect what members of a family
A: male and female
Q: Autosomal recessive disorders often result in what kind of defect/deficiencie?
A: enzyme deficiencies
Q: Autosomal recessive disorders usually effect how many generations in a family?
A: usually only one generation
Q: Bloom's syndrome is characterized by sensitivity to what as a result of
A: sensitivity to radiation as a result of a DNA repair defect
Q: Creatine and Urea are both made from?
A: Arginine
Q: Defects in structural genes often follow what pattern of inheritance?
A: Autosomal dominant
Q: Defiency of arylsulfatase A results in the accumulation of what molecule where
A: sulfatide in the brain, kidney, liver, and peripherla nerves. Characteristic of Metachromatic Leukodystrophy
Q: define genetic imprinting
A: when differences in phenotype depend on whether the mutation is of paternal or maternal origin
Q: define incomplete penetrance
A: when not all individuals with a mutant genotype show the mutant phenotype
Q: define Linkage Disequilibrium
A: the tendency for certain alleles at two linked loci to occur together more often thatn expected by chance, as measured in a population
Q: define pleiotropy
A: one gene has more than one effect on an individual's phenotype, autosomal dominant defects are oftne pleiotropic
Q: Define variable expression
A: nature and severity of the phenotype varies from one individual to another
Q: Fanconi's anemia is caused by what typr of agents
A: cross-linking agents
Q: Ganglioside is made up of what
A: Ceramide + oligosacharide + sialic acid
Q: Gaucher's disease is caused by a deficiency of
A: Beta-glucocerebrosidase
Q: Glucocerebroside accumulation in the brain, liver, spleen, and bone marrow are characteristic of
A: Gaucher's disease
Q: Hglycine is used to make what important compound
A: Porphyrin which is then used to make Heme
Q: Histamine is synthesized form what compound
A: Histidine
Q: How does adenosine deaminase defiency cause SCID
A: Purine salvage pathway. ADA normal converts adenosine to inosine
A: without it ATP & dATP build up inhibiting ribonucleotide reductase which prevents DNA synthesis lowering lymphocyte production
Q: How is Lesch-Nyhan syndrome inheritied andwhat is the result and symptoms
A: X-linked recessive; increase in uric acid production. Retardation, self mutalation, aggression, hyperuricemia, gout, and choreathetosis
Q: Hunter's syndrome is characterised by what biochemical problem and how is it inherited
A: deficiency of iduronate sulfatase; X-linked recessive
A: mild form of Hurler's
Q: In ataxia-telangiectasia DNA damage caused by what source cannot be repaired
A: X-rays
Q: in G6PD deficiency the decrease in NADPH can lead to _____ if exposed to _____
A: hemolytic anemia;oxidizing agents( fava beans, sulfonamides, primaquine) and antituberculosis.
Q: In PKU what builds up and what can be found in the urine
A: phenyalanine builds upe leading to phenylketones in the urine
Q: In PKU, what amino acid becomes essential
A: tyrosine.
Q: in the Hardy-Weinberg equation, what are the p and q and what is 2pq
A: p and q are each separate alleles; 2pq = heterozygote
Q: no male to male transmission is characteristic of what type of genetic disorders?
A: X-linked recessive
Q: Pompe's disease is caused by a defect in?
A: lysosomal alpha-1,4-glucosidase defiency
Q: Sickle cell anemia is caused by what defect and what is it's prevalence
A: AR single missense mutation in the beta globin; Q:400 blacks
Q: Siclkle cell anemia patients often present with
A: recurrent painful crisis and increased susceptibility to infections
Q: Skin sensitivity to UV light secondary to a DNA repair defect is characteristic of what?
A: xeroderma pigmentosum
Q: Sphingosine + fatty acid yields
A: ceramide
Q: the COL1A gene mutation is associated with what disease and what type of mutation is this
A: Osteogenesis imperfecta;dominant negitive mutation
Q: The main defect in Ataxia-telangiectasi is a ___
A: DNA repair defect
Q: The most common form of Osteogenesis imperfecta has what genetic problem and inheritance
A: abnormal Collagen Type I synthesis;Autosomal dominant
Q: the transporter for what amino acids is defective in cystinuria
A: COLA: Cys,Ornithine, Lysine and Arginine
Q: Thymidine dimers are formed by exposure of DNA to UV light, are the dimers formed on the opposing strands of a DNA molecule or on the same side?
A: dimers are on same side
Q: Tryptophan can be used to make what three chemicals
A: Niacin, 'Serotonin, melatonin
Q: Type III Glycogen storage disease is a defiency of ?
A: deficiency of debranching enzyme alpha-1,6-glucosidase
Q: What is the cause Tx and symptoms of Lactase intolerance?
A: Lactase defiency, avoid diary products or add lactse pills to diet
A: symptoms bloating, cramps, osmotic diarrhea
Q: What % of kids born to father with mitochondrial myopathie will be effected
A: none, mitochondrial myopathies are inherited from mitochondria which is only inherited from the mother
Q: What are the clinical signs of Krabbe's disease
A: optic atrophy, spasticity, early death
Q: What are the components of Cerebroside
A: Ceramide + glucose/galactose
Q: What are the components of Sphingomyelin
A: Ceramide + phosphorylcholine
Q: What are the components of sphingosine
A: serine + palmitate
Q: What are the findings and treatment of pyruvate dehydrogenase
A: neurologic defects; increase intake of ketogenic nutrients
Q: What are the findings in McArdles's disease and what is the problem
A: increased glycogen in skeletal muscle due to a Glycogen phosphorylase defiency
A: strenuous exercise cause myoglobinuria and painful cramps
Q: What are the findings in PKU and what is the treatment
A: Mental retardation, fair skin, eczema, musty body odor
A: Tx. Decreasee phenylalanin (nutrasweet) and increase tyrosine
Q: What are the findings in Pompe's disease and what is it alternate name
A: Cardiomegaly and systemic findings, leading to early death.
A: Pompe's trashes the Pump. (Heart, Liver and muscle)
A: Type II Glycogen storage disease
Q: What are the findings in Von Gierke's disease
A: severe fasting hypoglycemia, increased glycogen in the liver
Q: What are the four assumptions of the Hardy-Weinberg equilibrium
A: 1.There is no mutation occuring at the locus
A: 2. There is no selection for any of the geno types at the locus
A: 3. Random mating
A: 4. no migration in or out
Q: What are the purely ketogneic amino acids
A: lysine and leucine
Q: What are the signs and symptoms of essential fructosuria
A: asymptomatic, benign, Fructose appears in blood and urine
Q: what are the signs and symptoms of Homocystinuria
A: Homocysteine accumulates in urine and cystine becomes essential
A: Methionine and it's metabolites build up in blood
A: Mental retardation, osteoporosis, dislocation of the lens
Q: What are the symptoms of Alkaptonuria
A: Dark Urine from alkapton bodies; also connective tissue is dark, may have arthralgias. Bengin disease
Q: What are the symptoms of Fructose intolerance
A: hypoglycmeia, jaundice, cirrhosis
Q: What are the symptoms of Maple syrup Urine disease
A: CNS defects, mental retardation and death. Urine smells like maple syrup
Q: What biological chemicals are derived form phenylalanine
A: tyrosine, thyroxine Dopa dopamine NE, Epinephrine and Melanin
Q: What causes Essential Fructosuria
A: defect in fructokinase
Q: What causes Lesch-Nyhan syndrome
A: Absence of HGPRTase, (normally converts hypoxanthine to IMP and guanine to GMP) Lacks Nucleotide Salvage (LNS)-purines
Q: What do melanin and Norepinephrine have in common
A: both derived directly from dopamine
A: Phenylalanine to tyrosine to Dopa to Dopamin
Q: What does the term 'loss of heterozygosity' mean
A: when one allele of an allele pair is lost. An example is when a patient inherits or develops a mutation in a tumor suppressor gene and the complimentary allele is then lost to deletion/mutation.
A: The patient would not develop the cancer until the loss of the normal allele.
Q: What enzyme defiencies are associated with hemolytic anemia
A: Glycolytic enzyme deficiencies
A: 1. Hexokinase
A: 2.glucose-phosphate isomerase
A: 3.aldolase
A: 4.triose-phosphate isomerase
A: 5. phosphate-glycerate kinase
A: enolase
A: pyruvate kinase
Q: What event in embryology can cause albinism
A: lack of migration of neural crest cells to skin (form melanocytes)
Q: What genetic error can cause Severe Combined Immnuodeficiency (SCID)?
A: Adenosine deaminase deficiency
Q: what group of people can be seen with pyruvate dehydrognease deficiency
A: alcoholics due to B1 defiecincy
Q: What is a complication of cystinuria
A: cystine kidney stones
Q: What is a dominant negitive mutation?
A: a mutation that exerts a dominant effect because the body cannot produce enough of the normal gene product with only one allele functioning normally
Q: What is a good pnuemonic for the four glycogen storage diseases
A: Very-Von Gierke's
A: Poor-Pompes
A: Carbohydrate-Cori's
A: Metabolism-McArdles
Q: What is commonly associated with xeroderma pigementosa?
A: dry skin, melanoma and other cancers
Q: What is crucail to the diagnosis of an Autosomal dominant disease?
A: Family history
Q: What is genetic anticipation?
A: the severity of the diseas worsens or age of onset of disease is earlier in succeeding generations
Q: What is inheritance of G6PD dfiency and what population is effected more often
A: X-linked recessive; blacks
Q: What is NAD/NADP made form
A: Niacin, 'Serotonin, melatonin
Q: What is osteogenesis imperfecta often confused with
A: child abuse
Q: What is the biochemical defect in Metachromatic leukodystrophy and what is the inheritance pattern
A: deficiency of arylsulfatase A; Autosomal recessive
Q: What is the biochemical defect in Nieman-Pick disease and how is it inherited
A: deficiency of Beta-glucocerebrosidase; autosomal recessive
Q: What is the biochemical effect of G6PD defiency
A: decrease in NADPH which is necessary to reduce glutathione which in turn detoxifies free radicals and peroxides
Q: What is the cause of Cystinuria and what are the signs/symptoms
A: inheritied defect o the tubular amino acid transporter for Cystine, ornithine, Lysine and Arginine in kidneys
A: excess cystine in urine
Q: What is the cause of Fabry's disease and what is the common clinical problem
A: Alpha-galactosidase A deficiency; gives accumulation of ceramide trihexoside causing renal failure
Q: What is the cause of galactosemia?
A: Absence of galactose-1-phosphate uridyltransferase; accumualtion of toxic substances (galactitol)
Q: What is the characteristic defect in Hurler's syndrome
A: Alpha-L-iduronidase defiency leads to corneal clouding and mental retardation
Q: What is the characteristic findings in Neurofibromatosis
A: Multiple café-au-lait spots, neurofibromas increased tumor susceptibilty
Q: What is the clinical picture of a patient with cystic fibrosis
A: pulmonary infections, exocrine pancreatic insufficiency, infertility in men
Q: What is the clinical picture of Duchenne's muscular dystrophy
A: muscular weakness and degeneration
Q: What is the defect in Maple Syrup Urine disease
A: decreased Alpha-ketoacid dehydrogenase.
A: blocks degradation of branched amino acids
A: Ile. Val. Leu
Q: What is the epidemiology of lactose intolerance
A: Age-dependnet and/or hereditary (blacks and Asians)
Q: What is the etiology of Homocystinuria
A: defect in cystathionine synthase. Two forms:
A: 1. deficiency
A: 2.decreased affinity of synthase for pyridoxal phosphate (cofactor)
Q: What is the finding of Hunter's syndrome on H&P
A: mild mental retardation but no corneal clouding
Q: What is the formula for Hardy-Weinberg equilibrium?
A: p^2 +2pq + q^2 =1 and p+q=1
Q: What is the genetic mech. Of Cystic fibrosis and it's inheritance
A: AR; multiple loss-of-function mutations in a chloride channel
Q: What is the genetic mechanism of Duchenne's muscular dystrophy
A: X-linked recessive;caused by multiple loss-of-funtion mutations in a muscle protein
Q: What is the genetic mechanism of Fragile X MR
A: X-linked; progressive expansion of unstable DNA causes failure to express gene-encoding RNA-binding protein
Q: what is the genetic mechanism of Neurofibromatosis
A: AD, multiple loss-of function mutations in a signaling molecule
Q: What is the genetic problem in Down's Syndrome
A: trisomy 21 chromosomal imbalance
Q: What is the inheritance of Krabbe's disease
A: Autosomal recessive
Q: what is the inheritance pattern and carrier frequency in Tay-Sach's
A: Autosomal recessive; Q:30 in Jews of European descent and Q:300 in the general populaition
Q: What is the inheritance pattern of Ehlers-Danlos syndrome
A: 10 types of this syndrome
A: Type IV-Auto Dominant
A: Type VI-Auto Recessive
A: Type IX- X-linked recessive
Q: What is the inheritance pattern of Gaucher's disease
A: Autosomal recessive
Q: What is the inheritance pattern of xeroderma pigmentosa
A: autosomal recessive
Q: What is the inheritiance pattern of Fabry's disease
A: X-linked recessive
Q: What is the lab symptoms of G6PD defiency
A: Heinz Bodies: altered hemoglobin precipitate in RBC
Q: What is the most distinguishing finding in Tay-Sach's disease on Physical exam
A: cherry red Macula; these patients die by 3
Q: What is the pathogneumonic cell type founde in Gaucher's disease
A: Gaucher's cells with the characteristic 'crinkled paper' appearance of enlarged cytoplasm
Q: What is the pattern of inheritance of Leber's hereditary optic neuropathy?
A: mitochondrial inheritance
Q: What is the phenotype in Osteogenesis imperfecta
A: increased susceptibility to fractures;connective tissue fragility
Q: What is the phenotype of Down's syndrome
A: Mental and growth retardation, dysmorphic features, internal organ anomalies especially heart problems
Q: What is the phenotype of Fragile X
A: mental retardation, characteristic facial features, large testes
Q: What is the predominant problem in Ehlers-Danlos syndrome
A: Faulty collagen synthesis
Q: What is the prevalance of cystic fibrosis
A: Q:2000 whites; very rare among Asians
Q: What is the prevalandce of Neurofibromatosis
A: Q:3000 with 50% being new mutations
Q: What is the prevalence of Down's syndrome and what are the risk factors
A: Q:800; increased risk with advanced maternal age
Q: What is the prevalence of Duchenne's musc. dys.
A: Q:300; 33% new mutations
Q: What is the prevalence of Fragile X- associated mental retardation
A: Q:1500 males: can be in feamales is a multi-step process
Q: What is the prevalence of osteogenesis imperfecta
A: Q:10000,
Q: What is the prevalence of Phenylketonuria
A: Q:10000
Q: What is the priamry defect in Fructose intolerance and how is it inherited?
A: defiency of aldolase B, autosomal recessive
Q: What is the primary defect in Alkaptonuria
A: congenital defiency of homogentisic acid oxidase in the degradative pathway of tyrosine
Q: What is the primary defect(s) found in Phenylketoneuria
A: either 1.decreased phenylalanie hydroxylase
A: or 2. decreased tetrahydrobiopterin cofactor
Q: What is the rate-limiting enzyme in the Hexose-Monophosphate shunt?
A: Glucose-6-phosphate dehydrogenase
Q: What is the result of pyruvate dehydrognease deficiency
A: backup of substrate (pyruvate and alanine) resulting in lactic acidosis
Q: What is the specific defect in Xeroderma pigmentosa
A: defective excision repair such as uvr ABC exonuclease; have inability to repair thymidine dimer formed by UV light
Q: What is the treament of Cystinuria and what is a possible consequence of not treating
A: Acetazolide to alkinlize the urine
A: cystine kidney stones due to excess cysteine
Q: What is the treatment of fructose intolerance?
A: decrease intake of both fructose and sucrose (glucose + fructose)
Q: What is the treatment of Homocystinuria
A: 1. For a defiency in cystathionine synthase tx by decrease Met and increase Cys in diet
A: 2.for decreased affinity of synthase Tx by decrease vitamin B6 in diet
Q: What is the Tx of galactosemia?
A: Exclude galactose and lactose (galactose +glucose) form diet
Q: what offspring of females affected with a mitochondrial inherited disease will be effected?
A: all offspring can be effected
Q: what percent of offspring from two autosomal recessive carrier parents will be effected?
A: 25%
Q: what percent of sons of a heterazygous mother carrying an x-linked disease will be effected?
A: 50%
Q: What period of life do autosomal dominant defects present in?
A: often present clinically after puberty
Q: What three phenyl ketones build up in the urine of PKU patients
A: phenylacetate, phenyllactate, phenylpyruvate
Q: What to thyroxine and Dopa have in common
A: both derived form tyrosine
Q: What type of genetic error is usually more severe autosomal recessive or dominant?
A: AR disorders are often more severe
Q: What type of inheritance is transmitted only through mothers?
A: mitochondrial
Q: When do patients usually present with autosomal recessive disorders?
A: present in childhood
Q: Why are RBC so susceptible to Glycolytic enzyme def.
A: RBC's metabolize glucose anaerobically (no mitochondria) and depends on glycolysis
Q: Why do people with fructose intolerance become hypoglycemic?
A: deficent aldolase B causes the accumulation of Fructose 1-phosphate which acts as a phosphate sink and traps the phosphate. Decreased phosphate availability inhibits glycogenolysis and gluconeogenesis
Q: X-linked recessive disease is aften more severe in
A: males
BIOCHEM_LAB.TESTS
Q: How do you do a Northern Blot?
A: Electrophorese RNA on a gel
A: transfer to a filter
A: expose filter to a labeled DNA probe
A: visualize the DNA probe annealed to the desired RNA
Q: How do you do a Southern Blot?
A: Electrophorese DNA on a gel
A: transfer to a filter and denature the DNA
A: expose to a labeled DNA probe
A: visualize probe annealed to desired DNA fragment
Q: How do you do a Southwestern blot?
A: Separate protein by electrophoresis
A: transfer to a filter
A: expose to a labeled DNA probe
A: visualize DNA bound to desired protein
Q: How do you do a Western Blot?
A: Separate protein by electrophoresis
A: transfer to a filter
A: expose to a labeled antibody
A: visualize Ab bound to desired protein
Q: How do you do PCR? (4 steps)
A: 1. Heat DNA to denature.
A: 2. Cool DNA and let the primers aneal.
A: 3.Heat-stable polymerase replicates DNA following each premer
A: 4. Repeat
Q: What are some genetic diseases detectable by PCR?(11)
A: SCID, Lesh-Nyhan, CF, familial hypercholesterolemia
A: retinoblastoma, sickle cell, B-thalassemia, hemophilia A
A: and B, von Willebrand's dz, lysosomal dz, and glycogen stroage dz
Q: What gene is involved in cystic fibrosis?
A: CFTR
Q: What gene is involved in familial hypercholesterolemia?
A: LDL-R
Q: What gene is involved in Lesh-Nyhan syndrome?
A: HGPRT
Q: What gene is involved in retinoblastoma
A: Rb
Q: What gene is involved in SCID?
A: adenosine deaminase
Q: What gene is involved in Sickle cell and ?-thal?
A: ? globin gene
Q: What is an ELISA (enzyme linke immunosorbant assay)?
A: Rapid lab test in which an antibody or an antigen
A: (usually collected from a patient)
A: is exposed to an Ag or Ab liked to to an enzyme.
A: A positive test results in a Ag-Ab match
A: and is usually indicated by a color change
Q: What is PCR?
A: Lab procedure used to synthsize many copies of
A: a desired fragment of DNA
BIOCHEM_METABOLISM
Q: 1,3-BPG
A: 2,3-BPG via bisphosphoglycerate mutase
Q: Acyl
A: coenzyme A, lipoamide
Q: aldehydes
A: TPP
Q: Arachidonate
A: prostaglandins, -thromboxanes, -leukotrienes
Q: Associate the following signal molecule precursors.
A: j
Q: At body pH, what AA are negatively charged?
A: Arg and Lys
A: His is neutral at pH 7.4
Q: At body pH, what AA are positvely charged?
A: Asp and Glu
Q: ATP
A: cAMP via adenylate cyclase
Q: By what rxn order kinetics does alcohol dehydrogenase operate?
A: zero order kinetics
Q: CH(3) groups
A: SAM
Q: Choline
A: CDP-choline
Q: Choline
A: ACh via choline acetyltransferase
Q: CO(2)
A: biotin
Q: Contrast glucagon and insulin.
A: glucagon phosphorylates stuff, -turns glycogen synthase off and phosphorylase on
Q: Contrast hexokinase and glucokinase.
A: hexokinase throughout the body, -GK in liver and has lower affinity but higher capacity for glucose
Q: Contrast hexokinase and glucokinase.
A: only HK is feedback inhibited by G6P
Q: Does insulin affect glucose uptake of brain, RBC's and liver?
A: No
Q: Does insulin inhibit glucagon release by alpha cells of pancreas?
A: yes
Q: electrons
A: NADH, NADPH, FADH(2)
Q: Fructose-6-phosphate
A: fructose-1,6-bis-P via PFK (rate limiting step of glycolysis)
Q: Glucose
A: UDP-Glucose
Q: glutamate
A: GABA via glutamate decarboxylase (requires vit. B6)
Q: GTP
A: cGMP via guanylate cyclase
Q: How are ketone bodies excreted?
A: in urine
Q: How are ketone bodies formed?
A: FA and AA converted to acetoacetate and b-hydroxybutyrate
Q: How do the statin drugs work?
A: they inhibit HMG-CoA reductase
Q: How does disulfiram work?
A: inhibits acetylaldehyde dehydrogenase
Q: How does FA enter the cytosol?
A: via citrate shuttle
Q: How does FA enter the mitochondria?
A: via the carnitine shuttle
Q: How does lead affect heme synthesis?
A: inhibits ALA dehydratase and ferrochelatase
A: prevents incorporation of Fe
Q: How does the brain metabolize ketone bodies?
A: to 2 molecules of acetyl coA
Q: How is bilirubin removed from the body?
A: collected by liver, conjugated with glucuronate
A: excreted in bile
Q: How is ethanol metabolized?
A: ethanol oxidized to acetylaldehyde by alcohol dehyd and NAD+
A: acetalaldehyde ox to acetate by acetylaldehyde and NAD+
Q: How is FA entering the mitochondria inhibited?
A: by cytoplasmic malonyl-CoA
Q: How is glutamate converted to a-ketogluturate
A: By the loss of amonium and reduction of NADP
Q: How is glutamine converted to glutamate?
A: By the loss of amonium
Q: How is heme catabolized?
A: scavenged from RBC's and Fe+2 is reused
Q: How is LDL uptake undergone?
A: by target cells through receptor-mediated endocytosis
Q: How is most plasma cholesterol esterfied?
A: LCAT(lecethin-cholesterol acyltransferase)
Q: How is NAD+ generally used metabolically?
A: catabolic processes
Q: How is NADPH generally used metabolically?
A: anabolic processes (steroid and FA synthesis), repiratory burst, P-450
Q: How is TCA regulated?
A: by need for ATP and supply of NAD+
Q: How many ATP's per acetyl CoA?
A: 12
Q: How many ATP equivalants are needed to generate glucose from pyruvate?
A: 6
Q: How many enzyme activities does pyruvate dehydrognase possess
A: 3
Q: How many moles of ATP are generated aerobically through G3P shuttle?
A: 36 ATP
Q: How many moles of ATP are generated aerobically through malate shuttle?
A: 38 ATP
Q: How many moles of ATP are generated anaerobically?
A: 2 ATP
Q: In what tissue does heme synthesis occur (2)?
A: liver and bone marrow
Q: Insulin mneumonic
A: insulin moves glucose into cells
Q: Is Serum C peptide present with exogenous insulin intake?
A: No
Q: Kwashikor results from a protein deficient MEAL (mneumonic)
A: Malabsorption, Edema, Anemia, Liver (fatty)
Q: Mnemonic for gluconeogenesis irreversible enzymes?
A: Pathway Produces Fresh Glucose
Q: Mnemonic for SAM.
A: SAM the methyl donor man
Q: Name 6 common products of pyruvate metabolism?
A: glucose, lactate, Acetyl CoA+CO2, OAA, Alanine
Q: Name the activated carriers with associated moleclues.
Q: one carbon units
A: tetrahydrofolates
Q: phosphoryl
A: ATP
Q: T/F. Uncouplers stop ATP production?
A: FALSE
Q: Underproduction of heme causes what anemia?
A: microcytic hypochromic anemia
Q: What AA are required during periods of growth?
A: Arg and His
Q: What are clincial syndromes of this disorder?
A: xanthomas, atherosclerosis
A: homozygotes MI by age 30
Q: What are major pathways occur in the liver (8)?
A: most including gluconeogenesis, etc.
Q: What are the activators of glycgenolysis?
A: cAMP, and calcium ion
Q: What are the cofactors of pyruvate dehydrogenase (5)?
A: pyrophosphate, lipoic acid, CoA, FAD and NAD
Q: What are the components of a cholymicron remnant?
A: TG, FFA and apo E
Q: What are the components of a cholymicron?
A: TG, apo C-II, apo E, B-48, apo A
Q: What are the components of IDL?
A: less TG, CE, B-100 and E
Q: What are the components of LDL?
A: CE and B-100
Q: What are the components of VLDL?
A: TG, Cholesterol ester, B-100, CII and E
Q: What are the degradation product steps (3)?
A: heme to biliverdin to bilirubin
Q: What are the effector hormones of cholesterol synthesis?
A: insulin increases, glucagon decreases
Q: What are the effector hormones of glyc and pyr ox?
A: decreased glucagon and increased insulin
Q: What are the effector hormones of glycogenolysis?
A: insulin decreases, epi and glucagon increases
Q: What are the effector hormones of lipogenesis (2)?
A: insulin increases, glucagon decreases
Q: What are the electron transport chain inhibitors?
A: rotenone, antimycin A, CN-, CO
Q: What are the essential glucogenic/ketogenic AA?
A: Ile, Phe, Try
Q: What are the essential gluconeogenic AA?
A: Met, Thr, Val, Arg, His
Q: What are the essential ketogenic AA?
A: Leu and Lys
Q: What are the irreversible enzymes of gluconeogenesis (4)?
A: -pyruvate carboxylase, -PEP carboxykinase,-fructose-1,6-bisphosphotase, -glu-6-phosphotase
Q: What are the irreversible enzymes of glycolysis (4)?
A: -glucokinase/hexokinase,-PFK,-pyruvate kinase,-pyruvate dehdrogenase
Q: What are the main substrates used by adipose tissue (2)?
A: -glucose, -lipoprotein triacylglycerol
Q: What are the main substrates used by brain?
A: -glucose, -aa and ketone bodies when starved, -polyunsat FA in neonates
Q: What are the main substrates used by heart?
A: FFA, -some glucose, -lactate, -ketone bodies, VLDL and cholymicrom triacylglycerol
Q: What are the main substrates used by liver?
A: FFA, -glucose, -lactate, -glycerol, fructose, -AA
Q: What are the major activators of gluconeogenesis?
A: Acetyl CoA for pyruvate carboxylase and cAMP for PEP carboxykinase and F-1,6-bis-P
Q: What are the major activators of glycolysis and pyruvate oxidation?
A: AMP, fructose2,6-bis-P, fructose 1,6-bis-P in muscle, CoA, NAD, ADP and pyruvate
Q: What are the major metabolic pathways of the adipose tissue (2)?
A: - esterfication of FA's
A: - lipolysis
Q: What are the major metabolic pathways of the brain (2)?
A: -glycolysis,-aa metabolism
Q: What are the major metabolic pathways of the heart?
A: Aerobic pathways like B oxidation and TCA cycle
Q: What are the major products of the adipose tissue (2)?
A: -FFA, -glycerol
Q: What are the major products of the brain?
A: lactate
Q: What are the major products of the liver (10)?
A: glucose,-VLDL,-HDL,-ketone bodies,-urea,-uric acid, -bile acids, -plasma proteins
Q: What are the major regulatory enzymes of gluconeogenesis (3)?
A: pyruvate carboxylase, PEP carboxykinase and F-1,6-bis-P
Q: What are the major regulatory enzymes of glycolysis and pyruvate oxidation?
A: PFK and pyruvate dehydrogenase
Q: What are the major regulatory enzymes of cholesterol synthesis?
A: HMG-CoA reductase
Q: What are the products of the liver in the fasting state?
A: glucose and ketone bodies
Q: What are the products of the liver in the fed state?
A: glycogen and fats/VLDL
Q: What are the products of the TCA cycle?
A: 3NADH, 1FADH2, 2CO2, 1GTP per Acetyl CoA
Q: What are the some causes of hyperbilirubinemia (4)?
A: massive hemolysis, -block in catabolism, -diplaced from binding sites on albumin, decreased excretion
Q: What are the sources of hyperbilirubinemia (2)?
A: conjugated (direct/glucuronidated) and unconjugated(indirect/insoluble)
Q: What are the specialist enzymes of muscle (2)?
A: -lipoprotein lipase, and well developed resp chain
Q: What are the specialist enzymes of the adipose tissue (2)?
A: -lipoprotein lipase,-hormone sensitive lipase
Q: What are the specialist enzymes of the heart (2)?
A: -lipoprotein lipase, -respiratory chain well-developed
Q: What are the specialist enzymes of the liver?
A: -glucokinase,-glu-6-phosphotase,-glycerol kinase, -PEP carboxykinase, -fructokinase,-arginase,-HMG coA synthase and lyase, -7a-hydroxylase
Q: What are the three sites in the electron transport chain for active proton transfer?
A: NADH dehydrogenase, Cyt b/c1, and cytochrome oxidase aa3
Q: What can occur as an excess of cholymicrons (3)?
A: pancreatitis, lipemia retinalis and eruptive xanthomas
Q: What can occur as an excess of VLDL?
A: pancreatitis
Q: What catalyzes cholymicron to cholymicron remnant?
A: lipoprotein lipase
Q: What catalyzes IDL to LDL?
A: hepatic TG lipase
Q: What catalyzes VLDL to IDL?
A: lipoprotein lipase
Q: What causes a hangover?
A: acetylaldehyde accumulates
Q: What color is bilirubin and what is the condition of excess?
A: yellow, jaundice
Q: What complex is pyruvate dehydrogenase similar to?
A: a-ketogluturate dehydrogenase complex
Q: What do LT c4, D4 and E4 do (4)?
A: bronchconstriction, vasoconstriction, contract smooth muscle, increase vascular permeability
Q: What does breath smell like during ketoacidosis?
A: fruity(acetone)
Q: What does excess LDL cause(3)?
A: atherosclerosis, xanthomas, and arcus corneae
Q: What does oligomycin do to ETC?
A: ATPase inhibitor that increases proton gradient but not ATP production
Q: What does PGI stand for?
A: platelet gathering inhibitor
Q: What does the COX pathway yield?
A: thromboxanes, prostaglandins and prostacyclin
Q: What does the lipooxygenase pathway yield?
A: leukotrienes
Q: What does this stand for?
A: Ornithine, citrulline, carbamoyl-p, aspartate, arginosuccinate, fumurate, arginine, urea
Q: What enzyme catalyzes the rate limiting step of cholesterol syn.?
A: HMG-CoA reductase
Q: What induces the PPP?
A: insulin
Q: What is a major component of atherosclerotic plaque?
A: modified LDL
Q: What is an uncoupling agent to the ETC?
A: 2,4 DNP (dynamite)
Q: What is cofactor required for methionine (SAM) regeneration?
A: vitamin B12
Q: What is does PGI 2 inhibit (2)?
A: platelet aggregation and vasodilation
Q: What is familial hyper-cholesteremia?
A: AD genetic defect in LDL receptor
Q: What is Kwashikor?
A: protein malnutrition
Q: What is LT B4?
A: neutrophil chemotactic agent
Q: What is Marasmus?
A: Protein-calorie malnutrition resulting in tissue wasting
Q: What is the activator of lipogenesis?
A: Citrate
Q: What is the activator of PPP?
A: NADP+
Q: What is the clinical picture of Kwashikor?
A: small child with swollen belly
Q: What is the committed step of heme synthesis?
A: glycine+succ CoA to delta-aminolevulinate
Q: What is the composition of ATP?
A: Base(adenine), ribose, 3 phosphoryls
Q: What is the consequence of accumulated intermediates of heme synthesis?
A: porphyrias
Q: What is the easy way to remember the cofactors of PDH complex?
A: First 4 B vitamins + lipoic acid
Q: What is the effector hormone for glycogenesis?
A: Glucagon
Q: What is the energy content of the 2 phosphoanhydride bonds?
A: 7 kcal/mol each
Q: What is the functiion of HDL (2)?
A: transfers cholesterol from periphery to liver
A: acts as a repository for apoC and apoE
Q: What is the functioin of lipoprotein lipase?
A: FA uptake to cells from choly's and VLDL's
Q: What is the function of aminolevulinate (ALA) synthase ?
A: rate limiting step of heme synthesis
A: converts succinyl CoA and glycine to ALA
Q: What is the function of cholymicrons (2)?
A: delivers dietary TG to peripheral tissues
A: delivers dietary cholesterol to liver
Q: What is the function of hormone sensitive lipase?
A: degradation of stored TG's
Q: What is the function of LDL?
A: delivers hepatic cholesterol to peripheral tissues
Q: What is the function of phospholipase A2?
A: liberates arachidonic acid from cell membrane
Q: What is the function of PPP (3)?
A: -produces ribose-5-P from G6P for nucleotide synthsesis,-produces NADPH,-part of HMP shunt
Q: What is the function of SAM?
A: transfers methyl units to wide variety of receptors
Q: What is the function of the Cori Cycle?
A: transfers excess reducing equivalants from RBC's and muscle
A: to liver to allow muscle to function anaerobically
Q: What is the function of Tx A2 (2)?
A: platelet aggregation and vasoconstriction
Q: What is the function of VLDL?
A: Delivers hepatic TG to peripheral tisssue
Q: What is the inhibitor of lipogenesis (2)?
A: long-chain acyl-CoA, -cAMP
Q: What is the inhibitor of PPP?
A: NADPH
Q: What is the limiting reagent of ethanol metabolism?
A: NAD+
Q: What is the main substrate of fast twitch muscle?
A: glucose
Q: What is the main substrate of slow twitch muscle?
A: ketone bodies, -FFA, -triacylglycerol
Q: What is the major function of fast twitch muscle?
A: rapid movement
Q: What is the major function of slow twitch muscle?
A: sustained movement
Q: What is the major function of the a1 receptor?
A: increase vascular smooth muscle contraction
Q: What is the major function of the a2 receptor (2)?
A: -decrease sympathetic outflow, -decrease insulin release
Q: What is the major function of the B1 receptor (5)?
A: increase HR, -inc. conntractility, -inc. renin release,-inc. lipolysis, -inc. aq. Humor formation
Q: What is the major function of the B2 receptor (3)?
A: vasodilation, bronchodilation, inc. glucagon release
Q: What is the major function of the D1 receptor?
A: relax renal vascular smooth muscle
Q: What is the major function of the D2 receptor?
A: modulate transmitter release, esp. in brain
Q: What is the major function of the H1 receptor (4)?
A: increase mucous production, -contract bronchioles, -pruritis, -pain
Q: What is the major function of the H2 receptor (4)?
A: increase gastric acid secretion
Q: What is the major function of the liver?
A: service for the other organs and tissues
Q: What is the major function of the M1 receptor?
A: CNS
Q: What is the major function of the M2 receptor?
A: decrease heart rate
Q: What is the major function of the M3 receptor?
A: increase exocrine gland secretions
Q: What is the major function of the V1 receptor?
A: increase vascular smooth muscle contraction
Q: What is the major function of the V2 receptor?
A: increase water permeability and reabsorption in the renal collecting tubules
Q: What is the major inhibitor of glyc and pyr ox?
A: citrate (FA and ketone bodies) ATP and cAMP, -acetyl CoA, NADH, ATP
Q: What is the major inhibitor of TCA?
A: ATP, long-chain acyl-coA
Q: What is the major inhibitor of cholesterol synthesis (2)?
A: cholesterol and cAMP
Q: What is the major inhibitor of glycogenesis?
A: ADP and AMP and F-2,6-bis-P
Q: What is the major metabolic pathway of fast twitch muscle?
A: glycolysis
Q: What is the major metabolic pathway of slow twitch muscle?
A: Aerobic pathways like B oxidation and TCA cycle
Q: What is the major product of fast twitch muscle?
A: lactate
Q: What is the major product of slow twitch muscle?
A: lactate
Q: What is the major regulatory enzyme of glycogenolysis?
A: glycogen synthase
Q: What is the major regulatory enzyme of lipogenesis?
A: acetyl CoA carboxylase
Q: What is the major regulatory enzyme of pentose phosphate pathway (PPP)?
A: glucose-6-P dehydrogenase
Q: What is the major regulatory enzyme of TCA?
A: citrate synthase
Q: What is the mechanism for the ETC inhibitors?
A: directly block ETC, cause decreased proton gradient
Q: What is the mechanism for the ETC uncoupler?
A: inc. membrane permeability, decreases proton gradient and increases O2 consmption
Q: What is the mechanism of ethanol hypoglycemia?
A: NADH/NAD increases in liver
A: causes diversion of pyruvate to lactate and OAA to malate
A: inhibits gluconeogenesis and thus leads to hypoglycemia
Q: What is the mnemonic for the various substrates of the TCA cycle?
A: Cindy Is Kinky So She Fornicates More Often
Q: What is the mneumonic for essential AA?
A: PriVaTe TIM HALL
Q: What is the mneumonic for major apolipoproteins?
A: A-1 Activates LCAT
A: B-100 Binds to receptor
A: C-II is a Cofactor for LPL
A: E mediates Extra (remnant) uptake
Q: What is the pneumonic for the Urea cylce substrates?
A: Ordinarily, Careless Crappers Are Also Frivolous About Urination
Q: What is urobilinogen?
A: an intestinal intermediate
A: reabsorbed to blood and excreted in urine as urobilin
Q: What other physiological side affect occurs by this hypoglycemia?
A: fatty liver seen in chronic alcoholics
Q: What rxn does pyruvate dehydrogenase catalyze?
A: pyruvate+NAD+CoA goes to acetyl-CoA +CO2+NADH
Q: What second messenger system does Gi work through?
A: adenylcyclase reduces cAMP levels and protein kinase A is reduced
Q: What second messenger system does Gq work through?
A: phospholipase C, PIP2 to IP3 and DAG
A: DAG works through protein kinase C
A: IP3 increases IC calcium ion
Q: What second messenger system does Gs work through?
A: adenylcyclase converts ATP to cAMP to phosphorylate protein kinase A
Q: What some properties of bilirubin (3)?
A: sparingly water soluble
A: toxic to CNS
A: transported by albumin
Q: What step does this enzyme work on?
A: HMG-CoA to mevalonate
Q: What suppresses glycogenesis?
A: insulin
Q: What tissues require insulin for glucose uptake?
A: adipose and skeletal muscle
Q: What type of metabolism occurs in the both (3)?
A: -gluconeogenesis, -urea cycle, heme synthesis
Q: What type of metabolism occurs in the cytoplasm (5)?
A: glycolysis, -fatty acid synthesis, -HMP shunt, -protein synthesis (RER), -steroid synthesis (SER)
Q: What type of metabolism occurs in the mitochondria (3)?
A: Beta oxidation, -Acetyl-CoA production, -Kreb's cycle
Q: When are ketone bodies formed (2)?
A: during prolonged starvation
A: diabetic ketoacidosis
Q: Where are basic AA found in high amounts?
A: in Histones that bind to negative DNA
Q: Where are cholymicrons made?
A: small intestine
Q: Where are ketone bodies made?
A: liver
Q: Where does FA degradation occur?
A: mitochondria, where it will be used
Q: Where does FA synthesis occur?
A: cytosol
Q: Where is ALA synthase found and what inhibits it?
A: mitochondria, heme
Q: Where is HDL secreted from (2)?
A: liver and small intestine
Q: Where is insulin made?
A: B cells of pancreas
Q: Where is NADPH generated?
A: is a product of HMP shunt and the malate dehydrogenase rxn
Q: Where is SAM generated?
A: From ATP and methionine
Q: Where is VLDL made?
A: liver
Q: Which ketone body is detected in urine test (1 only)?
A: acetoacetate
BIOCHEM_PROTEINS
Q: Carbon monoxide has a greater affinity for what molecule?
A: CO has 200x greater affinity for hemoglobin than for oxygen
Q: Describe the subunits for hemoglobin?
A: hemoglobin is composed of 4 polypeptide subunits (2 alpha and 2 beta)
Q: During the cycle of the sodium pump, it is __.
A: phosphorylated
Q: How are enzymes regulated?
A: 1. enzyme concentration alteration (syntesis and/or destruction)
A: 2. covalent modification (eg. phosphorylation)
A: 3. proteolytic modification (zymogen)
A: 4. allosteric regulation (eg. feedback inhibition)
A: 5. transcriptional regulation (eg. steroid hormones)
Q: How does calcium cause skeletal muscle contraction?
A: Ca2+ -> activates troponin -> moves tropomyosin -> exposes actin-bining site -> allows actin-myosin interaction
Q: How does calcium cause smooth muscle contraction?
A: Ca2+ -> binds to calmodulin because smooth muscle doesn't have troponins!
Q: How does procollagen molecules become collagen fibrils?
A: procollagen molecules cleaved at terminal regions by peptidases to become insoluble tropocollagen, which aggregates to form fibrils
A: procollagen molecules are exocytosed into extracellular space, where this process occurs
Q: How is CO2 transported from tissue to lungs?
A: - binds to amino acids in globin chain (at N-terminus), not to heme
A: - favors T form of Hb (thus promotes O2 unloading)
Q: How is collagen fibillar structure reinforced?
A: by the formation of covalent lysine-hydroxylysine crosslinks between tropocollagen molecules
Q: How is hemoglobin structure regulated?
A: increased Cl-, H+, CO2, DPG, and temperature favor T form (low affinity of O2)--shifting the dissociation curve to the right, leading to increased O2 unloading
Q: Most cells are in which cell cycle phase?
A: G0
Q: On what cellular stuctures are microtubules found?
A: flagella, cilia, mitotic spindles
Q: On which cells is phosphotidylcholine (lecithin) a major component?
A: - RBC membranes
A: - myelin
A: - bile
A: - surfactant (DPPC--dipalmitoyl phosphatidylcholine)
A: - also used in the esterification of cholesterol
Q: Only the cytoplasmic side of membrane contains what?
A: glycosylated lipids or proteins
Q: The lower the Km, the (higher/lower/remains same) the affinity
A: higher
Q: What are the 2 forms of hemoglobin?
A: - T (taut) form has low affininty for oxygen
A: - R (relaxed) form has 300x higher affinity for oxygen
A: Hb exerts positive cooperativity and negative allostery, accounting for the sigmoid-shaped O2 disassociation curve (which myoglobin doesn't have)
A: [Hint: When you're RELAXED, you do your job better (carry more O2)]
Q: What are the cell cycle phases?
A: Mitosis (Prophase-Metaphase-Anaphase-Telophase)
A: G1 (Gap or Growth)
A: S (Synthesis of DNA)
A: G2 (Gap or Growth)
A: G0 (quiescent G1 phase)
Q: What are the characteristics of a microtubule?
A: - cylindrical structure 24nm in dia and variable length
A: - helical array of polymerized dimers of alpha- and beta-tubulin (13 per circumference)
A: - each dimer has 2 GTP bound
A: - grows slowly, collapses quickly
A: - involved in slow axoplasmic transport in neurons
Q: What are the characteristics of competitive inhibitors?
A: - resemble substrates
A: - bind reversibly to active sites of enzymes
A: - high substrate concentrations overcomes effect of inhibitors
A: - Vmax remains unchanges
A: - Km increases compared to unhibited
A: [see graph & hint, p 168]
Q: What are the characteristics of noncompetitive inhibitors?
A: - doesn't resemble substrate
A: - bind to enzyme but not necessarily at active site
A: - inhibition can't be overcome by high substrate concentration
A: - Vmax decreases
A: - Km remains unchanged compared to uninhibited
A: [see graph & hint, p 168]
Q: What cell cycle phases are variable in duration?
A: G1 and G0
Q: What drugs act on microtubules?
A: - mebendazole/thiabendazole (antihelmintic)
A: - taxol (anti-breast cancer)
A: - griseofulvin (antifungal)
A: -cholchicine (anti-gout)
Q: What drugs inhibits the sodium pump?
A: - Ouabain inhibits the pump by binding to the K+ site
A: - cardiac glycosides (digoxin, digitoxin) also inhibit the pump, causing increased cardiac contractility
Q: What is methemoglobinemia?
A: blood disorder where methemoglobin, an oxidized form of hemoglobin (ferric, Fe3+) that does not bind O2 as readily. Iron in Hb is normally in a reduced state (ferrous, Fe2+)
Q: What is the difference between collagen fibril and collagen molecule?
A: fibril is made of molecules
A: collagen fibril--many staggered collagen molecules linked by lysyl oxidase
A: collagen molecule--3 collagen alpha chains, usually of Gly-x-y (x and y = pro, OH-pro, or OH-lys)
Q: What is the first step in forming collagen from prolyl and lysyl residues? Where does it occur? What nutrient does it require?
A: hydroxylation
A: endoplasmic reticulum
A: vitamin C
Q: What is the plasma membrane composition?
A: - cholesterol (~50%, promotes membrane stability)
A: - phospholipids (~50%)
A: - sphingolipids
A: -glycolipids
A: -proteins
Q: What is the sodium pump?
A: Na-K ATPase
Q: What molecules, how many of them, and in what direction are moved across the membrane by the sodium pump?
A: 3 Na go out and 2 K go in
Q: Where is the sodium pump?
A: on the membrane, with the ATP site on the cytoplasmic side of the pump
Q: Which cell cycle phase is shorter in rapidly dividing cells?
A: rapidly dividing cells have a shorter G1 phase
Q: Which cell cycle phase is usually shortest?
A: mitosis
BIOCHEM_VITAMINS
Q: Arthralgia's, fatigue, headaches, skin changes, sore throat, alopecia are symptoms foundin what vitamin deficiency
A: Vit A (Retinal)
Q: How does sarcoidosis cause hypercalcemia?
A: in sarcoid, epitheliod macrophages convert vitamin D into it's active form leading to increased absorption of calcium
Q: How many ATP are made from Niacin
A: Niacin=NAD
A: niacin is B3=3 ATP
Q: What are the characteristic findings seen in Riboflavin deficiencies
A: Riboflavin is B2
A: 2 C's=cheilosis and Corneal vascularization and also Angular stomatitis
Q: What are the fat soluble vitamins
A: D,A,K,E
Q: What are the findings in Vit D excess?
A: Hypercalcemia, loss of appetite, stupor
Q: What are the possible causes of hypercalcemia?
A: 1. Vit D intoxication
A: 2. Malignancy
A: 3. Hyperparathyroidism
A: 4. Milk-alkali syndrome
A: 5. Sarcoidosis
A: 6. Paget's disease of bone
Q: What are the signs and symptoms of vit B12 deficiency?
A: 1. Macrocytic megaloblastic anemia
A: 2. Neurologic symptoms-optic neuropathy, subacute combined degeneration
A: 3.glossitis
Q: What are the signs of Biotin deficiency and what are possilble causes?
A: dermatitis, enteritis
A: antiobiotic use and ingestion of raw eggs
Q: What are the signs of Folate deficiency?
A: Macrocytic megaloblastic anemia
A: sprue
Q: What are the symptoms in Vit B5 deficiency
A: dermatitis, enterititis, alopecia, adrenal insufficiency
Q: What are the symptoms of Pellagra
A: 3 D's Diarrhea, Dermatitis, Dementia, and also Beefy glossitis
Q: What are the usual causes of Vit B12 deficiency?
A: 1. Malabsorption- Sprue, enteritis, Diphyllobthrium latum (Dr. Lohr's fish tapeworm)
A: 2.lack of intrinsic factor (pernicious anemia)
A: 3. Absence of the terminal ileum- Crohn's disease or surgery
Q: What are the water soluble vitamins
A: B complex vitamins (B1,2,3,5,6,12), Vit C, Biotin, Folate
Q: What can induce pyridoxine deficiency? Symptoms?
A: INH and oral contraceptives
A: convulsion, hyperirritability
Q: What clotting factors are Vit K dependent and what anti-clotting drug acts as a Vit K antagonist?
A: Factors II, VII, IX, X and Protein C and S
A: Warfarin
Q: what disease is characterized by polyneuritis, cardiac pathology and edema and what is the cause
A: Beriberi (Ber1BerI), due to Vit B1 deficiency
Q: What diseases conditions are caused by Vitamin D deficiency?
A: Rickets in kids
A: Osteomalacia in adults
A: hypocalcemic tetany
Q: What diseases is caused by Vit C deficiency and what are the findings?
A: Scurvy
A: swollen gums, bruising, anemia, poor wound healing
Q: What is B12 used for in the body?
A: Cofactor for homocysteine methylation and methylmalonyl-CoA handling
Q: What is Niacin's function in the body and from what can it be derived
A: part of NAD, NADP and is derived from tryptophan
Q: What is the active form of Vitamin D?
A: 1,25 (OH)2 D3 = active form
Q: What is the alternate name of Vit B3, problems in deficiency, common cause of defieciency
A: niacin
A: Pellagra
A: Hartnup disease, malignant carcinoid syndrome, and INH
Q: What is the alternate name of vitamin B1 and what are the characteristic diseases of it's deficiency
A: Beriberi and Wernicke-Korsakoff syndrome
Q: What is the folic acid precursor in bacteria and what antibiotics exploit this fact?
A: PABA is the precursor
A: sulfa drugs and dapsone are PABA analogs
Q: What is the form of vitamin D consumed in milk?
A: D2 = ergocalciferol
Q: What is the form of Vitamin D found in sun-exposed skin?
A: D3 = cholecalciferol
Q: What is the function and alternate name of Vit. B2
A: cofactor in oxidation and reduction (FAD,FMN)
A: RiboFlavin
Q: What is the function of Biotin?
A: Cofactor for carboxylations
A: 1. Pyruvate to oxaloacetate
A: 2. Acetyl-CoA to malonyl Co-A
A: 3. Prprionyl-CoA to methylmalonyl-CoA
Q: What is the function of folic acid?
A: coenzyme for 1-carbon transfer;methylation reactions
A: important for the synthesis of nitrogenous bases in DNA and RNA
Q: What is the function of Vit A, it's alternate name, and symptoms in deficiency
A: visual pigments (retinal)
A: retinol
A: night blindness and dry skin
Q: What is the function of Vit B1
A: it becomes Thiamine Pyrophosphate (TPP) and is used in:
A: oxidative decarboxylation of Alpha-keto acids (pyruvate, Alpha-ketoglutarate
A: cofactor for tranketolase in the HMP shunt
Q: What is the function of Vit B6
A: B6 (pyridoxine) is converted to pyridoxal phosphate
A: a cofactore in transamination reactions (ALT & AST), decarboxylation, and trans-sulfuration
Q: What is the function of Vit E?
A: antioxidant; especially in Erythrocytes where it protects them from hemolysis
A: Vit E is for Erythrocytes
Q: What is the function of vitamin C?
A: 1. Cross linking of collagen-hydroxylation of proline and lysine in collagen synthesis
A: keeping iron in the Fe2+ reduced state making it more absorbable
A: 3. Cofactor for coverting dopamine to norepinephrine
Q: What is the function of Vitamin D?
A: increase intestinal absorption of Calcium and phosphate
Q: What is the function of Vitamin K?
A: catalyzes gamma-carboxylation of glutamic acid residues on various proteins concerned with clotting.
Q: What is the most common vitamin deficiency in the United States?
A: Foilic Acid
Q: What is the rule of 2's for Vit B2
A: 2 F's, 2C's and 2ATP
A: 2 F's=FAD&FMN
A: 2 C's = signs of deficiency cheilosis and corneal vascularization
A: oxidation of FADH2 leads to 2 ATP
Q: What is the sotrage form of Vitamin D?
A: 25-OH D3
Q: What is the source of Vit B12 and what is B12's other name
A: found only in animal products
A: cobalamin
Q: What is vit B5's function and alternate name
A: constituent of CoA, part of fatty acid synthase. Cofactor for acyl transfers
A: Pantothenate (Pantothen-A is in Co-A)
Q: What manifestation is specific to wet beriberi?
A: high output cardiac failure (dilated cardiomyopathy)
Q: What molecule in egg white binds up Biotin and causes deficiency
A: Avidin
Q: What problems do you see in Vit K deficiency?
A:
Q: At which end of the tRNA is the aa bound?
A: The amino acid is covalently bound to the 3' end of the tRNA.
Q: Can RNA polymerase initiate chains?
A: Yes.
Q: Define transition.
A: Substituting purine for purine or pyrimidine for pyrimidine.
Q: Define transversion.
A: Substituting purine for pyrimidine or vice versa.
Q: Define tRNA wobble.
A: Accurate base pairing is required only in the first 2 nucleotide positions of an mRNA codon, so codons differing in the
A: 3rd 'wobble' position may code for the same tRNA/amino acid.
Q: Describe DNA replication.
A: Origin of replication: continuous DNA synthesis on leading strand and discontinuous (Okazaki fragments) on lagging strand.
A: Primase makes an RNA primer on which DNA polymerase can initiate replication.
Q: Describe DNA replication continued
A: DNA polymerase reaches primer of preceding fragment; 5' to 3' exonuclease activity of DNA polymerase I degrades RNA primer;
A: DNA ligase seals; 3' to 5' exonuclease activity of DNA polymerase 'proofreads' each added nucleotide.
Q: Describe topoisomerase activity
A: DNA topoisomerases create a nick in the helix to relieve supercoils
Q: Describe Euchromatin
A: Less condensed (vs. Heterochromatin), transcriptionally active
Q: Describe Heterochromatin
A: Condensed, transcriptionally inactive
Q: Describe key structural differences between nucleotides.
A: 1) Purines (A,G) have 2 rings.
A: 2) Pyrimidines (C,T,U) have 1 ring
A: 3) Guanine has a ketone.
A: 4) Thymine has a methyl
Q: Describe single-strand, excision repair.
A: Excision repair-specific glycosylase recognizes and removes damaged base.
A: Endonuclease makes a break several bases to the 5' side.
A: Exonuclease removes short stretch of nucleotides.
A: DNA polymerase fills gap.
A: DNA ligase seals.
Q: Describe the difference between Eukaryotic Vs. Bacterial, viral and plasmid origin of replications
A: Eukaryotic genome has multiple origins of replication.
A: Bacteria, viruses and plasmids have only one origin of replication.
Q: Describe the main difference in eukaryotic and prokaryotic synthesis of RNA.
A: Eukaryotes have 3 different RNA polymerases ('I, II, III synthesize RMT')
A: and prokaryotes have 1 RNA polymerase (which makes all 3 kinds of RNA).
Q: Describe the method by which introns are removed from primary mRNA transcript.
A: Introns are precisely spliced out of primary mRNA transcripts.
A: A lariat-shaped intermediate is formed.
A: Small nuclear ribonucleoprotein particles (snRNP) facilitate splicing by binding to primary mRNA transcripts and forming spliceosomes.
Q: Describe the number of bonds per purine-pyrimidine pair. Which is stronger?
A: G-C bond (3 H-bonds)
A: A-T bond (2 H-bonds
A: G-C bond is stronger
Q: Describe the structure of Chromatin.
A: Condensed by (-) charged DNA looped around (+) charged histones (nucleosome bead).
A: H1 ties the nucleosome together in a string (30 nm fiber)
Q: Describe tRNA structure.
A: 75-90 nucleotides, cloverleaf form, anticodon end is opposite 3' aminoacyl end.
A: All tRNAs both eukaryotic and prokaryotic, have CCA at 3' end along with a high percentage of chemically modified bases.
A: The amino acid is covalently bound to the 3' end of the tRNA.
Q: Does RNA polymerase have a proof reading function?
A: No.
Q: How do purines and pyrimidines interact, molecularly?
A: Purines and pyrimidines pair (A-T, G-C) via H-bonds
Q: How does RNA polymerase II open DNA?
A: RNA polymerase II opens DNA at promoter site
A: (A-T rich upstream sequence- TATA and CAAT)
Q: How is the original RNA transcript processed in eukaryotes? (3)
A: 1) Capping on 5' end (7-methyl G)
A: 2)Polyadenylation on 3' end ( =200 As)
A: 3) Splicing out of introns
Q: In eukaryotes, what must occur before an newly synthesized RNA transcript leaves the nucleus?
A: Only processed RNA is transported out the nucleus of eukaryotes.
Q: Name 3 types of RNA
A: 1) mRNA
A: 2) rRNA
A: 3) tRNA
Q: Name the charged histones around which (-) charged DNA loops (nucleosome core).
A: H2A, H2B, H3, H4 histones
Q: Name the enzyme responsible for the synthesis of RNA in prokaryotes.
A: RNA polymerase
Q: Name the enzymes involved in ss-DNA repair. (5)
A: 1) specific glycosylase.
A: 2) endonuclease.
A: 3) exonuclease.
A: 4) Dan polymerase.
A: 5) DNA ligase.
Q: Name the enzymes responsible for the synthesis of eukaryotic RNA.
A: RNA polymerase I
A: RNA polymerase II
A: RNA polymerase III
Q: What are exons?
A: Exons contain the actual genetic information coding for a protein
Q: What are four types of mutations that can occur in DNA?
A: 1) Silent
A: 2) Missense
A: 3) Nonsense
A: 4) Frame shift
Q: What are introns?
A: Introns are intervening noncoding segments of DNA
Q: What are the four features of the Genetic Code?
A: 1) Unambiguous
A: 2) Degenerate
A: 3) Commaless, non-overlapping
A: 4)Universal
Q: What atoms link aa in a protein chain?
A: Amino acids are linked N to C
Q: What changes occur in DNA structure during mitosis?
A: In mitosis, DNA condenses to form mitotic chromosomes
Q: What codon sequence is found at the 3' end of all tRNAs?
A: All tRNAs, both eukaryotic and prokaryotic, have CCA at 3' end.
Q: What direction is DNA synthesized in?
A: 5' > 3'.
A: Remember that the 5' of the incoming nucleotide bears the triphosphate (energy source for the bond).
A: The 3' hydroxyl of the nascent chain is the target.
Q: What direction is protein synthesized in?
A: Protein synthesis also proceed in the 5' to 3' (5' > 3')
Q: What direction is RNA synthesized in?
A: 5' > 3'.
A: Remember that the 5' of the incoming nucleotide bears the triphosphate (energy source for the bond).
A: The 3' hydroxyl of the nascent chain is the target.
Q: What does the AUG mRNA sequence code for?
A: AUG codes for methionin, which may be removed before translation is completed. In prokaryotes the initial AUG codes for a formyl-methionin (f-met).
Q: What does the P in P-site stand for?
Q: What does the A in A-site stand for?
A: P-site: peptidyl;
A: A-site: aminoacyl;
Q: What does the statement, 'the genetic code is commaless' mean?
Q: What is the exception to this rule?
A: The code is non-overlapping.
A: The exception are some viruses
Q: What does the statement, 'the genetic code is degenerate' mean?
A: More than one codon may code for the same amino acid
Q: What does the statement, 'the genetic code is unambiguous' mean?
A: Each codon specifies only one amino acid
Q: What does the statement, 'the genetic code is universal' mean?
Q: What are the exceptions (4)?
A: The same code is used in all lifeforms.
A: The exceptions are 1. mitochondria, 2. archaeobacteria, 3. Mycoplasma, 4. some yeasts
Q: What enzyme is responsible for 'charging' tRNA? How does it work?
A: Aminoacyl-tRNA synthetase.
A: This enzyme (one per aa, uses ATP) scrutinizes aa before and after it binds to tRNA.
A: If incorrect, bond is hydrolyzed by synthetase. The aa-tRNA bond has energy for formation of peptide bond.
Q: What inhibits RNA polymerase II?
A: alpha-amanitin inhibits RNA polymerase II
Q: What is a conservative missense mutation?
A: Mutation results in a different aa encoded, but that new aa is similar in chemical structure to the original code
Q: What is a frameshift mutation? What is usually the effect on the encoded protein?
A: A change in DNA resulting in misreading of all nucleotides downstream.
A: Usually results in a truncated protein.
Q: What is a missense mutation?
A: Mutation results in a different aa encoded.
Q: What is a nonsense mutation?
A: A change in DNA resulting in an early stop codon.
Q: What is a promoter?
A: Site where RNA polymerase and multiple other transcription factors bind to DNA upstream from gene locus.
Q: What is a silent mutation? What usually causes a silent mutation?
A: Mutation results in the same aa encoded. Often the base change is in the 3rd position of the codon
Q: What is a snRNP? What is its function?
A: snRNP = small nuclear ribonucleoprotein.
A: snRNPs facilitate splicing by binding to primary mRNA transcripts and forming spliceosomes.
Q: What is an enhancer?
A: Stretch of Dan that alters gene expression by binding transcription facts. May be located close to, far from, or even within (an intron) the gene whose expression it regulates.
Q: What is an Okazaki fragment?
A: The discontinuous DNA synthesized on the lagging strand during DNA replication
Q: What is hnRNA?
A: hnRNA = heterogeneous nuclear RNA
A: The initial RNA transcript is called hnRNA
Q: What is responsible for the accuracy of amino acid selection during peptide synthesis?
A: Aminoacyl-tRNA synthetase and binding of charged tRNA to the codon are responsible for accuracy of amino acid selection.
Q: What is the broad classification of nucleotides? (2)
A: Purines (A, G) and Pyrimidines (C, T, U)
Q: What is the difference between hnRNA and mRNA?
A: hnRNA = the initial RNA transcript
A: mRNA = capped and tailed transcript
Q: What is the difference between thymine and uracil?
A: Uracil found in RNA
A: Thymine found in DNA
Q: What is the function of DNA ligase during DNA Replication?
A: DNA ligase seals synthesized DNA into a continuous strand
Q: What is the function of DNA polymerase during DNA Replication? (2)
A: 5' to 3' exonuclease activity of DNA polymerase I degrades RNA primer;
A: 3' to 5' exonuclease activity of DNA polymerase 'proofreads' each added nucleotide.
Q: What is the function of DNA topoisomerase during DNA Replication?
A: DNA topoisomerases create a nick in the helix to relieve supercoils
Q: What is the function of primase in DNA Replication?
A: Primase makes an RNA primer on which DNA polymerase can initiate replication.
Q: What is the function of RNA polymerase I?
A: RNA polymerase I makes rRNA
Q: What is the function of RNA polymerase II?
A: RNA polymerase II makes mRNA
Q: What is the function of RNA polymerase III?
A: RNA polymerase III makes tRNA
Q: What is the mRNA initiation codon?
A: AUG, or rarely GUG
Q: What is the mRNA stop codons? (3)
A: UGA (U Go Away)
A: UAA (U Are Away)
A: UAG (U Are Gone)
Q: What is the result of 'mischarged' tRNA?
A: A mischarged tRNA (bound to wrong aa) reads usual codon but inserts wrong amino acid.
Q: What is the role of endonuclease in ss-DNA repair?
A: Endonuclease makes a break several bases to the 5' side.
Q: What is the role of excision repair-specific glycosylase in ss-DNA repair
A: Recognizes and removes damaged base.
Q: What is the role of exonuclease in ss-DNA repair?
A: Exonuclease removes short stretch of nucleotides.
Q: What prevents an incorrect aa-tRNA pairing?
A: If incorrect, the aa-tRNA bond is hydrolyzed by aminoacyl-tRNA synthetase.
Q: What role does histone H1 play in chromatin structure?
A: H1 ties the nucleosome together in a string (30nm fiber)
Q: What supplies the energy for formation of peptide bond?
A: The aa-tRNA bond has energy for formation of peptide bond.
Q: What would most likely be the result of a mutation of the promoter sequence?
A: Promoter mutation commonly results in dramatic decrease in amount of gene transcribed.
Q: When is ATP used in protein synthesis? When is GTP used in protein synthesis?
A: ATP is used in tRNA charging,
A: whereas GTP is used in binding of tRNA ribosome and for translocations.
Q: When is recombination involved in DNA repair?
A: If both strands are damaged, repair may proceed via recombination with undamaged homologous chromosome.
Q: Where does RNA processing occur in eukaryotes?
A: RNA processing occurs in the nucleus.
Q: Which is the largest type of RNA?
A: mRNA (massive)
Q: Which is the most abundant type of RNA?
A: rRNA (rampant)
Q: Which is the smallest type of RNA?
A: tRNA (tiny)
Q: Which nucleotide position in the codon has room for 'wobble'?
A: Codons differing in the 3rd 'wobble' position may code for the same tRNA/amino acid
BIOCHEM_GENETICS
Q: Von Geirke's disease is a result of?
A: Glucose-6-phosphatase deficiency; also known as Type I Glycogen Storage disease
Q: A build up of sphingomyelin and cholesterol in reticuloendothelial and parenchymal cells and tissues is found in what disease
A: Niemann-Pick disease
Q: A child is born with multiple fractures and blue sclera what is the diagnosis
A: Osteogenesis imperfecta;disease of abnormal collagen synthesis resulting in fractures and translucent Conn tiss over chorioid causing the blue sclera
Q: A congenital deficiency of tyrosinase would lead to
A: Albinism, can't synthesize melanin from tyrosine
Q: A patient presents with cataracts, hepatosplenomegaly, and mental retardation, what is the Dx?
A: Galactosemia
Q: A patient presents with corneal clouding and mental retardation that is, based on family history, inherited in an Autsomal recessive pattern, you impress your intern with a Dx of
A: Hurler's syndrome
Q: A patient presents with
A: 1. Hyperextensible skin
A: 2. Tendency to bleed
A: 3.Hypermobile joints
A: you astutely Dx them with
A: Ehlers-Danlos syndrome
Q: Absence of Galactosylceramide Beta-galactosidase leads to thebuild up of what compound in what disease
A: accumulation of galactocerebroside in the brain; Krabbe's disease
Q: Absence of hexosaminidase A results in the acumulation of what molecule that is characteristic of what disease
A: GM2-ganglioside accumulation; Tay-Sachs disease
Q: albinism increase risk of developing what
A: skin cancer
Q: Autosomal dominant defects will effect what members of a family
A: male and female
Q: Autosomal recessive disorders often result in what kind of defect/deficiencie?
A: enzyme deficiencies
Q: Autosomal recessive disorders usually effect how many generations in a family?
A: usually only one generation
Q: Bloom's syndrome is characterized by sensitivity to what as a result of
A: sensitivity to radiation as a result of a DNA repair defect
Q: Creatine and Urea are both made from?
A: Arginine
Q: Defects in structural genes often follow what pattern of inheritance?
A: Autosomal dominant
Q: Defiency of arylsulfatase A results in the accumulation of what molecule where
A: sulfatide in the brain, kidney, liver, and peripherla nerves. Characteristic of Metachromatic Leukodystrophy
Q: define genetic imprinting
A: when differences in phenotype depend on whether the mutation is of paternal or maternal origin
Q: define incomplete penetrance
A: when not all individuals with a mutant genotype show the mutant phenotype
Q: define Linkage Disequilibrium
A: the tendency for certain alleles at two linked loci to occur together more often thatn expected by chance, as measured in a population
Q: define pleiotropy
A: one gene has more than one effect on an individual's phenotype, autosomal dominant defects are oftne pleiotropic
Q: Define variable expression
A: nature and severity of the phenotype varies from one individual to another
Q: Fanconi's anemia is caused by what typr of agents
A: cross-linking agents
Q: Ganglioside is made up of what
A: Ceramide + oligosacharide + sialic acid
Q: Gaucher's disease is caused by a deficiency of
A: Beta-glucocerebrosidase
Q: Glucocerebroside accumulation in the brain, liver, spleen, and bone marrow are characteristic of
A: Gaucher's disease
Q: Hglycine is used to make what important compound
A: Porphyrin which is then used to make Heme
Q: Histamine is synthesized form what compound
A: Histidine
Q: How does adenosine deaminase defiency cause SCID
A: Purine salvage pathway. ADA normal converts adenosine to inosine
A: without it ATP & dATP build up inhibiting ribonucleotide reductase which prevents DNA synthesis lowering lymphocyte production
Q: How is Lesch-Nyhan syndrome inheritied andwhat is the result and symptoms
A: X-linked recessive; increase in uric acid production. Retardation, self mutalation, aggression, hyperuricemia, gout, and choreathetosis
Q: Hunter's syndrome is characterised by what biochemical problem and how is it inherited
A: deficiency of iduronate sulfatase; X-linked recessive
A: mild form of Hurler's
Q: In ataxia-telangiectasia DNA damage caused by what source cannot be repaired
A: X-rays
Q: in G6PD deficiency the decrease in NADPH can lead to _____ if exposed to _____
A: hemolytic anemia;oxidizing agents( fava beans, sulfonamides, primaquine) and antituberculosis.
Q: In PKU what builds up and what can be found in the urine
A: phenyalanine builds upe leading to phenylketones in the urine
Q: In PKU, what amino acid becomes essential
A: tyrosine.
Q: in the Hardy-Weinberg equation, what are the p and q and what is 2pq
A: p and q are each separate alleles; 2pq = heterozygote
Q: no male to male transmission is characteristic of what type of genetic disorders?
A: X-linked recessive
Q: Pompe's disease is caused by a defect in?
A: lysosomal alpha-1,4-glucosidase defiency
Q: Sickle cell anemia is caused by what defect and what is it's prevalence
A: AR single missense mutation in the beta globin; Q:400 blacks
Q: Siclkle cell anemia patients often present with
A: recurrent painful crisis and increased susceptibility to infections
Q: Skin sensitivity to UV light secondary to a DNA repair defect is characteristic of what?
A: xeroderma pigmentosum
Q: Sphingosine + fatty acid yields
A: ceramide
Q: the COL1A gene mutation is associated with what disease and what type of mutation is this
A: Osteogenesis imperfecta;dominant negitive mutation
Q: The main defect in Ataxia-telangiectasi is a ___
A: DNA repair defect
Q: The most common form of Osteogenesis imperfecta has what genetic problem and inheritance
A: abnormal Collagen Type I synthesis;Autosomal dominant
Q: the transporter for what amino acids is defective in cystinuria
A: COLA: Cys,Ornithine, Lysine and Arginine
Q: Thymidine dimers are formed by exposure of DNA to UV light, are the dimers formed on the opposing strands of a DNA molecule or on the same side?
A: dimers are on same side
Q: Tryptophan can be used to make what three chemicals
A: Niacin, 'Serotonin, melatonin
Q: Type III Glycogen storage disease is a defiency of ?
A: deficiency of debranching enzyme alpha-1,6-glucosidase
Q: What is the cause Tx and symptoms of Lactase intolerance?
A: Lactase defiency, avoid diary products or add lactse pills to diet
A: symptoms bloating, cramps, osmotic diarrhea
Q: What % of kids born to father with mitochondrial myopathie will be effected
A: none, mitochondrial myopathies are inherited from mitochondria which is only inherited from the mother
Q: What are the clinical signs of Krabbe's disease
A: optic atrophy, spasticity, early death
Q: What are the components of Cerebroside
A: Ceramide + glucose/galactose
Q: What are the components of Sphingomyelin
A: Ceramide + phosphorylcholine
Q: What are the components of sphingosine
A: serine + palmitate
Q: What are the findings and treatment of pyruvate dehydrogenase
A: neurologic defects; increase intake of ketogenic nutrients
Q: What are the findings in McArdles's disease and what is the problem
A: increased glycogen in skeletal muscle due to a Glycogen phosphorylase defiency
A: strenuous exercise cause myoglobinuria and painful cramps
Q: What are the findings in PKU and what is the treatment
A: Mental retardation, fair skin, eczema, musty body odor
A: Tx. Decreasee phenylalanin (nutrasweet) and increase tyrosine
Q: What are the findings in Pompe's disease and what is it alternate name
A: Cardiomegaly and systemic findings, leading to early death.
A: Pompe's trashes the Pump. (Heart, Liver and muscle)
A: Type II Glycogen storage disease
Q: What are the findings in Von Gierke's disease
A: severe fasting hypoglycemia, increased glycogen in the liver
Q: What are the four assumptions of the Hardy-Weinberg equilibrium
A: 1.There is no mutation occuring at the locus
A: 2. There is no selection for any of the geno types at the locus
A: 3. Random mating
A: 4. no migration in or out
Q: What are the purely ketogneic amino acids
A: lysine and leucine
Q: What are the signs and symptoms of essential fructosuria
A: asymptomatic, benign, Fructose appears in blood and urine
Q: what are the signs and symptoms of Homocystinuria
A: Homocysteine accumulates in urine and cystine becomes essential
A: Methionine and it's metabolites build up in blood
A: Mental retardation, osteoporosis, dislocation of the lens
Q: What are the symptoms of Alkaptonuria
A: Dark Urine from alkapton bodies; also connective tissue is dark, may have arthralgias. Bengin disease
Q: What are the symptoms of Fructose intolerance
A: hypoglycmeia, jaundice, cirrhosis
Q: What are the symptoms of Maple syrup Urine disease
A: CNS defects, mental retardation and death. Urine smells like maple syrup
Q: What biological chemicals are derived form phenylalanine
A: tyrosine, thyroxine Dopa dopamine NE, Epinephrine and Melanin
Q: What causes Essential Fructosuria
A: defect in fructokinase
Q: What causes Lesch-Nyhan syndrome
A: Absence of HGPRTase, (normally converts hypoxanthine to IMP and guanine to GMP) Lacks Nucleotide Salvage (LNS)-purines
Q: What do melanin and Norepinephrine have in common
A: both derived directly from dopamine
A: Phenylalanine to tyrosine to Dopa to Dopamin
Q: What does the term 'loss of heterozygosity' mean
A: when one allele of an allele pair is lost. An example is when a patient inherits or develops a mutation in a tumor suppressor gene and the complimentary allele is then lost to deletion/mutation.
A: The patient would not develop the cancer until the loss of the normal allele.
Q: What enzyme defiencies are associated with hemolytic anemia
A: Glycolytic enzyme deficiencies
A: 1. Hexokinase
A: 2.glucose-phosphate isomerase
A: 3.aldolase
A: 4.triose-phosphate isomerase
A: 5. phosphate-glycerate kinase
A: enolase
A: pyruvate kinase
Q: What event in embryology can cause albinism
A: lack of migration of neural crest cells to skin (form melanocytes)
Q: What genetic error can cause Severe Combined Immnuodeficiency (SCID)?
A: Adenosine deaminase deficiency
Q: what group of people can be seen with pyruvate dehydrognease deficiency
A: alcoholics due to B1 defiecincy
Q: What is a complication of cystinuria
A: cystine kidney stones
Q: What is a dominant negitive mutation?
A: a mutation that exerts a dominant effect because the body cannot produce enough of the normal gene product with only one allele functioning normally
Q: What is a good pnuemonic for the four glycogen storage diseases
A: Very-Von Gierke's
A: Poor-Pompes
A: Carbohydrate-Cori's
A: Metabolism-McArdles
Q: What is commonly associated with xeroderma pigementosa?
A: dry skin, melanoma and other cancers
Q: What is crucail to the diagnosis of an Autosomal dominant disease?
A: Family history
Q: What is genetic anticipation?
A: the severity of the diseas worsens or age of onset of disease is earlier in succeeding generations
Q: What is inheritance of G6PD dfiency and what population is effected more often
A: X-linked recessive; blacks
Q: What is NAD/NADP made form
A: Niacin, 'Serotonin, melatonin
Q: What is osteogenesis imperfecta often confused with
A: child abuse
Q: What is the biochemical defect in Metachromatic leukodystrophy and what is the inheritance pattern
A: deficiency of arylsulfatase A; Autosomal recessive
Q: What is the biochemical defect in Nieman-Pick disease and how is it inherited
A: deficiency of Beta-glucocerebrosidase; autosomal recessive
Q: What is the biochemical effect of G6PD defiency
A: decrease in NADPH which is necessary to reduce glutathione which in turn detoxifies free radicals and peroxides
Q: What is the cause of Cystinuria and what are the signs/symptoms
A: inheritied defect o the tubular amino acid transporter for Cystine, ornithine, Lysine and Arginine in kidneys
A: excess cystine in urine
Q: What is the cause of Fabry's disease and what is the common clinical problem
A: Alpha-galactosidase A deficiency; gives accumulation of ceramide trihexoside causing renal failure
Q: What is the cause of galactosemia?
A: Absence of galactose-1-phosphate uridyltransferase; accumualtion of toxic substances (galactitol)
Q: What is the characteristic defect in Hurler's syndrome
A: Alpha-L-iduronidase defiency leads to corneal clouding and mental retardation
Q: What is the characteristic findings in Neurofibromatosis
A: Multiple café-au-lait spots, neurofibromas increased tumor susceptibilty
Q: What is the clinical picture of a patient with cystic fibrosis
A: pulmonary infections, exocrine pancreatic insufficiency, infertility in men
Q: What is the clinical picture of Duchenne's muscular dystrophy
A: muscular weakness and degeneration
Q: What is the defect in Maple Syrup Urine disease
A: decreased Alpha-ketoacid dehydrogenase.
A: blocks degradation of branched amino acids
A: Ile. Val. Leu
Q: What is the epidemiology of lactose intolerance
A: Age-dependnet and/or hereditary (blacks and Asians)
Q: What is the etiology of Homocystinuria
A: defect in cystathionine synthase. Two forms:
A: 1. deficiency
A: 2.decreased affinity of synthase for pyridoxal phosphate (cofactor)
Q: What is the finding of Hunter's syndrome on H&P
A: mild mental retardation but no corneal clouding
Q: What is the formula for Hardy-Weinberg equilibrium?
A: p^2 +2pq + q^2 =1 and p+q=1
Q: What is the genetic mech. Of Cystic fibrosis and it's inheritance
A: AR; multiple loss-of-function mutations in a chloride channel
Q: What is the genetic mechanism of Duchenne's muscular dystrophy
A: X-linked recessive;caused by multiple loss-of-funtion mutations in a muscle protein
Q: What is the genetic mechanism of Fragile X MR
A: X-linked; progressive expansion of unstable DNA causes failure to express gene-encoding RNA-binding protein
Q: what is the genetic mechanism of Neurofibromatosis
A: AD, multiple loss-of function mutations in a signaling molecule
Q: What is the genetic problem in Down's Syndrome
A: trisomy 21 chromosomal imbalance
Q: What is the inheritance of Krabbe's disease
A: Autosomal recessive
Q: what is the inheritance pattern and carrier frequency in Tay-Sach's
A: Autosomal recessive; Q:30 in Jews of European descent and Q:300 in the general populaition
Q: What is the inheritance pattern of Ehlers-Danlos syndrome
A: 10 types of this syndrome
A: Type IV-Auto Dominant
A: Type VI-Auto Recessive
A: Type IX- X-linked recessive
Q: What is the inheritance pattern of Gaucher's disease
A: Autosomal recessive
Q: What is the inheritance pattern of xeroderma pigmentosa
A: autosomal recessive
Q: What is the inheritiance pattern of Fabry's disease
A: X-linked recessive
Q: What is the lab symptoms of G6PD defiency
A: Heinz Bodies: altered hemoglobin precipitate in RBC
Q: What is the most distinguishing finding in Tay-Sach's disease on Physical exam
A: cherry red Macula; these patients die by 3
Q: What is the pathogneumonic cell type founde in Gaucher's disease
A: Gaucher's cells with the characteristic 'crinkled paper' appearance of enlarged cytoplasm
Q: What is the pattern of inheritance of Leber's hereditary optic neuropathy?
A: mitochondrial inheritance
Q: What is the phenotype in Osteogenesis imperfecta
A: increased susceptibility to fractures;connective tissue fragility
Q: What is the phenotype of Down's syndrome
A: Mental and growth retardation, dysmorphic features, internal organ anomalies especially heart problems
Q: What is the phenotype of Fragile X
A: mental retardation, characteristic facial features, large testes
Q: What is the predominant problem in Ehlers-Danlos syndrome
A: Faulty collagen synthesis
Q: What is the prevalance of cystic fibrosis
A: Q:2000 whites; very rare among Asians
Q: What is the prevalandce of Neurofibromatosis
A: Q:3000 with 50% being new mutations
Q: What is the prevalence of Down's syndrome and what are the risk factors
A: Q:800; increased risk with advanced maternal age
Q: What is the prevalence of Duchenne's musc. dys.
A: Q:300; 33% new mutations
Q: What is the prevalence of Fragile X- associated mental retardation
A: Q:1500 males: can be in feamales is a multi-step process
Q: What is the prevalence of osteogenesis imperfecta
A: Q:10000,
Q: What is the prevalence of Phenylketonuria
A: Q:10000
Q: What is the priamry defect in Fructose intolerance and how is it inherited?
A: defiency of aldolase B, autosomal recessive
Q: What is the primary defect in Alkaptonuria
A: congenital defiency of homogentisic acid oxidase in the degradative pathway of tyrosine
Q: What is the primary defect(s) found in Phenylketoneuria
A: either 1.decreased phenylalanie hydroxylase
A: or 2. decreased tetrahydrobiopterin cofactor
Q: What is the rate-limiting enzyme in the Hexose-Monophosphate shunt?
A: Glucose-6-phosphate dehydrogenase
Q: What is the result of pyruvate dehydrognease deficiency
A: backup of substrate (pyruvate and alanine) resulting in lactic acidosis
Q: What is the specific defect in Xeroderma pigmentosa
A: defective excision repair such as uvr ABC exonuclease; have inability to repair thymidine dimer formed by UV light
Q: What is the treament of Cystinuria and what is a possible consequence of not treating
A: Acetazolide to alkinlize the urine
A: cystine kidney stones due to excess cysteine
Q: What is the treatment of fructose intolerance?
A: decrease intake of both fructose and sucrose (glucose + fructose)
Q: What is the treatment of Homocystinuria
A: 1. For a defiency in cystathionine synthase tx by decrease Met and increase Cys in diet
A: 2.for decreased affinity of synthase Tx by decrease vitamin B6 in diet
Q: What is the Tx of galactosemia?
A: Exclude galactose and lactose (galactose +glucose) form diet
Q: what offspring of females affected with a mitochondrial inherited disease will be effected?
A: all offspring can be effected
Q: what percent of offspring from two autosomal recessive carrier parents will be effected?
A: 25%
Q: what percent of sons of a heterazygous mother carrying an x-linked disease will be effected?
A: 50%
Q: What period of life do autosomal dominant defects present in?
A: often present clinically after puberty
Q: What three phenyl ketones build up in the urine of PKU patients
A: phenylacetate, phenyllactate, phenylpyruvate
Q: What to thyroxine and Dopa have in common
A: both derived form tyrosine
Q: What type of genetic error is usually more severe autosomal recessive or dominant?
A: AR disorders are often more severe
Q: What type of inheritance is transmitted only through mothers?
A: mitochondrial
Q: When do patients usually present with autosomal recessive disorders?
A: present in childhood
Q: Why are RBC so susceptible to Glycolytic enzyme def.
A: RBC's metabolize glucose anaerobically (no mitochondria) and depends on glycolysis
Q: Why do people with fructose intolerance become hypoglycemic?
A: deficent aldolase B causes the accumulation of Fructose 1-phosphate which acts as a phosphate sink and traps the phosphate. Decreased phosphate availability inhibits glycogenolysis and gluconeogenesis
Q: X-linked recessive disease is aften more severe in
A: males
BIOCHEM_LAB.TESTS
Q: How do you do a Northern Blot?
A: Electrophorese RNA on a gel
A: transfer to a filter
A: expose filter to a labeled DNA probe
A: visualize the DNA probe annealed to the desired RNA
Q: How do you do a Southern Blot?
A: Electrophorese DNA on a gel
A: transfer to a filter and denature the DNA
A: expose to a labeled DNA probe
A: visualize probe annealed to desired DNA fragment
Q: How do you do a Southwestern blot?
A: Separate protein by electrophoresis
A: transfer to a filter
A: expose to a labeled DNA probe
A: visualize DNA bound to desired protein
Q: How do you do a Western Blot?
A: Separate protein by electrophoresis
A: transfer to a filter
A: expose to a labeled antibody
A: visualize Ab bound to desired protein
Q: How do you do PCR? (4 steps)
A: 1. Heat DNA to denature.
A: 2. Cool DNA and let the primers aneal.
A: 3.Heat-stable polymerase replicates DNA following each premer
A: 4. Repeat
Q: What are some genetic diseases detectable by PCR?(11)
A: SCID, Lesh-Nyhan, CF, familial hypercholesterolemia
A: retinoblastoma, sickle cell, B-thalassemia, hemophilia A
A: and B, von Willebrand's dz, lysosomal dz, and glycogen stroage dz
Q: What gene is involved in cystic fibrosis?
A: CFTR
Q: What gene is involved in familial hypercholesterolemia?
A: LDL-R
Q: What gene is involved in Lesh-Nyhan syndrome?
A: HGPRT
Q: What gene is involved in retinoblastoma
A: Rb
Q: What gene is involved in SCID?
A: adenosine deaminase
Q: What gene is involved in Sickle cell and ?-thal?
A: ? globin gene
Q: What is an ELISA (enzyme linke immunosorbant assay)?
A: Rapid lab test in which an antibody or an antigen
A: (usually collected from a patient)
A: is exposed to an Ag or Ab liked to to an enzyme.
A: A positive test results in a Ag-Ab match
A: and is usually indicated by a color change
Q: What is PCR?
A: Lab procedure used to synthsize many copies of
A: a desired fragment of DNA
BIOCHEM_METABOLISM
Q: 1,3-BPG
A: 2,3-BPG via bisphosphoglycerate mutase
Q: Acyl
A: coenzyme A, lipoamide
Q: aldehydes
A: TPP
Q: Arachidonate
A: prostaglandins, -thromboxanes, -leukotrienes
Q: Associate the following signal molecule precursors.
A: j
Q: At body pH, what AA are negatively charged?
A: Arg and Lys
A: His is neutral at pH 7.4
Q: At body pH, what AA are positvely charged?
A: Asp and Glu
Q: ATP
A: cAMP via adenylate cyclase
Q: By what rxn order kinetics does alcohol dehydrogenase operate?
A: zero order kinetics
Q: CH(3) groups
A: SAM
Q: Choline
A: CDP-choline
Q: Choline
A: ACh via choline acetyltransferase
Q: CO(2)
A: biotin
Q: Contrast glucagon and insulin.
A: glucagon phosphorylates stuff, -turns glycogen synthase off and phosphorylase on
Q: Contrast hexokinase and glucokinase.
A: hexokinase throughout the body, -GK in liver and has lower affinity but higher capacity for glucose
Q: Contrast hexokinase and glucokinase.
A: only HK is feedback inhibited by G6P
Q: Does insulin affect glucose uptake of brain, RBC's and liver?
A: No
Q: Does insulin inhibit glucagon release by alpha cells of pancreas?
A: yes
Q: electrons
A: NADH, NADPH, FADH(2)
Q: Fructose-6-phosphate
A: fructose-1,6-bis-P via PFK (rate limiting step of glycolysis)
Q: Glucose
A: UDP-Glucose
Q: glutamate
A: GABA via glutamate decarboxylase (requires vit. B6)
Q: GTP
A: cGMP via guanylate cyclase
Q: How are ketone bodies excreted?
A: in urine
Q: How are ketone bodies formed?
A: FA and AA converted to acetoacetate and b-hydroxybutyrate
Q: How do the statin drugs work?
A: they inhibit HMG-CoA reductase
Q: How does disulfiram work?
A: inhibits acetylaldehyde dehydrogenase
Q: How does FA enter the cytosol?
A: via citrate shuttle
Q: How does FA enter the mitochondria?
A: via the carnitine shuttle
Q: How does lead affect heme synthesis?
A: inhibits ALA dehydratase and ferrochelatase
A: prevents incorporation of Fe
Q: How does the brain metabolize ketone bodies?
A: to 2 molecules of acetyl coA
Q: How is bilirubin removed from the body?
A: collected by liver, conjugated with glucuronate
A: excreted in bile
Q: How is ethanol metabolized?
A: ethanol oxidized to acetylaldehyde by alcohol dehyd and NAD+
A: acetalaldehyde ox to acetate by acetylaldehyde and NAD+
Q: How is FA entering the mitochondria inhibited?
A: by cytoplasmic malonyl-CoA
Q: How is glutamate converted to a-ketogluturate
A: By the loss of amonium and reduction of NADP
Q: How is glutamine converted to glutamate?
A: By the loss of amonium
Q: How is heme catabolized?
A: scavenged from RBC's and Fe+2 is reused
Q: How is LDL uptake undergone?
A: by target cells through receptor-mediated endocytosis
Q: How is most plasma cholesterol esterfied?
A: LCAT(lecethin-cholesterol acyltransferase)
Q: How is NAD+ generally used metabolically?
A: catabolic processes
Q: How is NADPH generally used metabolically?
A: anabolic processes (steroid and FA synthesis), repiratory burst, P-450
Q: How is TCA regulated?
A: by need for ATP and supply of NAD+
Q: How many ATP's per acetyl CoA?
A: 12
Q: How many ATP equivalants are needed to generate glucose from pyruvate?
A: 6
Q: How many enzyme activities does pyruvate dehydrognase possess
A: 3
Q: How many moles of ATP are generated aerobically through G3P shuttle?
A: 36 ATP
Q: How many moles of ATP are generated aerobically through malate shuttle?
A: 38 ATP
Q: How many moles of ATP are generated anaerobically?
A: 2 ATP
Q: In what tissue does heme synthesis occur (2)?
A: liver and bone marrow
Q: Insulin mneumonic
A: insulin moves glucose into cells
Q: Is Serum C peptide present with exogenous insulin intake?
A: No
Q: Kwashikor results from a protein deficient MEAL (mneumonic)
A: Malabsorption, Edema, Anemia, Liver (fatty)
Q: Mnemonic for gluconeogenesis irreversible enzymes?
A: Pathway Produces Fresh Glucose
Q: Mnemonic for SAM.
A: SAM the methyl donor man
Q: Name 6 common products of pyruvate metabolism?
A: glucose, lactate, Acetyl CoA+CO2, OAA, Alanine
Q: Name the activated carriers with associated moleclues.
Q: one carbon units
A: tetrahydrofolates
Q: phosphoryl
A: ATP
Q: T/F. Uncouplers stop ATP production?
A: FALSE
Q: Underproduction of heme causes what anemia?
A: microcytic hypochromic anemia
Q: What AA are required during periods of growth?
A: Arg and His
Q: What are clincial syndromes of this disorder?
A: xanthomas, atherosclerosis
A: homozygotes MI by age 30
Q: What are major pathways occur in the liver (8)?
A: most including gluconeogenesis, etc.
Q: What are the activators of glycgenolysis?
A: cAMP, and calcium ion
Q: What are the cofactors of pyruvate dehydrogenase (5)?
A: pyrophosphate, lipoic acid, CoA, FAD and NAD
Q: What are the components of a cholymicron remnant?
A: TG, FFA and apo E
Q: What are the components of a cholymicron?
A: TG, apo C-II, apo E, B-48, apo A
Q: What are the components of IDL?
A: less TG, CE, B-100 and E
Q: What are the components of LDL?
A: CE and B-100
Q: What are the components of VLDL?
A: TG, Cholesterol ester, B-100, CII and E
Q: What are the degradation product steps (3)?
A: heme to biliverdin to bilirubin
Q: What are the effector hormones of cholesterol synthesis?
A: insulin increases, glucagon decreases
Q: What are the effector hormones of glyc and pyr ox?
A: decreased glucagon and increased insulin
Q: What are the effector hormones of glycogenolysis?
A: insulin decreases, epi and glucagon increases
Q: What are the effector hormones of lipogenesis (2)?
A: insulin increases, glucagon decreases
Q: What are the electron transport chain inhibitors?
A: rotenone, antimycin A, CN-, CO
Q: What are the essential glucogenic/ketogenic AA?
A: Ile, Phe, Try
Q: What are the essential gluconeogenic AA?
A: Met, Thr, Val, Arg, His
Q: What are the essential ketogenic AA?
A: Leu and Lys
Q: What are the irreversible enzymes of gluconeogenesis (4)?
A: -pyruvate carboxylase, -PEP carboxykinase,-fructose-1,6-bisphosphotase, -glu-6-phosphotase
Q: What are the irreversible enzymes of glycolysis (4)?
A: -glucokinase/hexokinase,-PFK,-pyruvate kinase,-pyruvate dehdrogenase
Q: What are the main substrates used by adipose tissue (2)?
A: -glucose, -lipoprotein triacylglycerol
Q: What are the main substrates used by brain?
A: -glucose, -aa and ketone bodies when starved, -polyunsat FA in neonates
Q: What are the main substrates used by heart?
A: FFA, -some glucose, -lactate, -ketone bodies, VLDL and cholymicrom triacylglycerol
Q: What are the main substrates used by liver?
A: FFA, -glucose, -lactate, -glycerol, fructose, -AA
Q: What are the major activators of gluconeogenesis?
A: Acetyl CoA for pyruvate carboxylase and cAMP for PEP carboxykinase and F-1,6-bis-P
Q: What are the major activators of glycolysis and pyruvate oxidation?
A: AMP, fructose2,6-bis-P, fructose 1,6-bis-P in muscle, CoA, NAD, ADP and pyruvate
Q: What are the major metabolic pathways of the adipose tissue (2)?
A: - esterfication of FA's
A: - lipolysis
Q: What are the major metabolic pathways of the brain (2)?
A: -glycolysis,-aa metabolism
Q: What are the major metabolic pathways of the heart?
A: Aerobic pathways like B oxidation and TCA cycle
Q: What are the major products of the adipose tissue (2)?
A: -FFA, -glycerol
Q: What are the major products of the brain?
A: lactate
Q: What are the major products of the liver (10)?
A: glucose,-VLDL,-HDL,-ketone bodies,-urea,-uric acid, -bile acids, -plasma proteins
Q: What are the major regulatory enzymes of gluconeogenesis (3)?
A: pyruvate carboxylase, PEP carboxykinase and F-1,6-bis-P
Q: What are the major regulatory enzymes of glycolysis and pyruvate oxidation?
A: PFK and pyruvate dehydrogenase
Q: What are the major regulatory enzymes of cholesterol synthesis?
A: HMG-CoA reductase
Q: What are the products of the liver in the fasting state?
A: glucose and ketone bodies
Q: What are the products of the liver in the fed state?
A: glycogen and fats/VLDL
Q: What are the products of the TCA cycle?
A: 3NADH, 1FADH2, 2CO2, 1GTP per Acetyl CoA
Q: What are the some causes of hyperbilirubinemia (4)?
A: massive hemolysis, -block in catabolism, -diplaced from binding sites on albumin, decreased excretion
Q: What are the sources of hyperbilirubinemia (2)?
A: conjugated (direct/glucuronidated) and unconjugated(indirect/insoluble)
Q: What are the specialist enzymes of muscle (2)?
A: -lipoprotein lipase, and well developed resp chain
Q: What are the specialist enzymes of the adipose tissue (2)?
A: -lipoprotein lipase,-hormone sensitive lipase
Q: What are the specialist enzymes of the heart (2)?
A: -lipoprotein lipase, -respiratory chain well-developed
Q: What are the specialist enzymes of the liver?
A: -glucokinase,-glu-6-phosphotase,-glycerol kinase, -PEP carboxykinase, -fructokinase,-arginase,-HMG coA synthase and lyase, -7a-hydroxylase
Q: What are the three sites in the electron transport chain for active proton transfer?
A: NADH dehydrogenase, Cyt b/c1, and cytochrome oxidase aa3
Q: What can occur as an excess of cholymicrons (3)?
A: pancreatitis, lipemia retinalis and eruptive xanthomas
Q: What can occur as an excess of VLDL?
A: pancreatitis
Q: What catalyzes cholymicron to cholymicron remnant?
A: lipoprotein lipase
Q: What catalyzes IDL to LDL?
A: hepatic TG lipase
Q: What catalyzes VLDL to IDL?
A: lipoprotein lipase
Q: What causes a hangover?
A: acetylaldehyde accumulates
Q: What color is bilirubin and what is the condition of excess?
A: yellow, jaundice
Q: What complex is pyruvate dehydrogenase similar to?
A: a-ketogluturate dehydrogenase complex
Q: What do LT c4, D4 and E4 do (4)?
A: bronchconstriction, vasoconstriction, contract smooth muscle, increase vascular permeability
Q: What does breath smell like during ketoacidosis?
A: fruity(acetone)
Q: What does excess LDL cause(3)?
A: atherosclerosis, xanthomas, and arcus corneae
Q: What does oligomycin do to ETC?
A: ATPase inhibitor that increases proton gradient but not ATP production
Q: What does PGI stand for?
A: platelet gathering inhibitor
Q: What does the COX pathway yield?
A: thromboxanes, prostaglandins and prostacyclin
Q: What does the lipooxygenase pathway yield?
A: leukotrienes
Q: What does this stand for?
A: Ornithine, citrulline, carbamoyl-p, aspartate, arginosuccinate, fumurate, arginine, urea
Q: What enzyme catalyzes the rate limiting step of cholesterol syn.?
A: HMG-CoA reductase
Q: What induces the PPP?
A: insulin
Q: What is a major component of atherosclerotic plaque?
A: modified LDL
Q: What is an uncoupling agent to the ETC?
A: 2,4 DNP (dynamite)
Q: What is cofactor required for methionine (SAM) regeneration?
A: vitamin B12
Q: What is does PGI 2 inhibit (2)?
A: platelet aggregation and vasodilation
Q: What is familial hyper-cholesteremia?
A: AD genetic defect in LDL receptor
Q: What is Kwashikor?
A: protein malnutrition
Q: What is LT B4?
A: neutrophil chemotactic agent
Q: What is Marasmus?
A: Protein-calorie malnutrition resulting in tissue wasting
Q: What is the activator of lipogenesis?
A: Citrate
Q: What is the activator of PPP?
A: NADP+
Q: What is the clinical picture of Kwashikor?
A: small child with swollen belly
Q: What is the committed step of heme synthesis?
A: glycine+succ CoA to delta-aminolevulinate
Q: What is the composition of ATP?
A: Base(adenine), ribose, 3 phosphoryls
Q: What is the consequence of accumulated intermediates of heme synthesis?
A: porphyrias
Q: What is the easy way to remember the cofactors of PDH complex?
A: First 4 B vitamins + lipoic acid
Q: What is the effector hormone for glycogenesis?
A: Glucagon
Q: What is the energy content of the 2 phosphoanhydride bonds?
A: 7 kcal/mol each
Q: What is the functiion of HDL (2)?
A: transfers cholesterol from periphery to liver
A: acts as a repository for apoC and apoE
Q: What is the functioin of lipoprotein lipase?
A: FA uptake to cells from choly's and VLDL's
Q: What is the function of aminolevulinate (ALA) synthase ?
A: rate limiting step of heme synthesis
A: converts succinyl CoA and glycine to ALA
Q: What is the function of cholymicrons (2)?
A: delivers dietary TG to peripheral tissues
A: delivers dietary cholesterol to liver
Q: What is the function of hormone sensitive lipase?
A: degradation of stored TG's
Q: What is the function of LDL?
A: delivers hepatic cholesterol to peripheral tissues
Q: What is the function of phospholipase A2?
A: liberates arachidonic acid from cell membrane
Q: What is the function of PPP (3)?
A: -produces ribose-5-P from G6P for nucleotide synthsesis,-produces NADPH,-part of HMP shunt
Q: What is the function of SAM?
A: transfers methyl units to wide variety of receptors
Q: What is the function of the Cori Cycle?
A: transfers excess reducing equivalants from RBC's and muscle
A: to liver to allow muscle to function anaerobically
Q: What is the function of Tx A2 (2)?
A: platelet aggregation and vasoconstriction
Q: What is the function of VLDL?
A: Delivers hepatic TG to peripheral tisssue
Q: What is the inhibitor of lipogenesis (2)?
A: long-chain acyl-CoA, -cAMP
Q: What is the inhibitor of PPP?
A: NADPH
Q: What is the limiting reagent of ethanol metabolism?
A: NAD+
Q: What is the main substrate of fast twitch muscle?
A: glucose
Q: What is the main substrate of slow twitch muscle?
A: ketone bodies, -FFA, -triacylglycerol
Q: What is the major function of fast twitch muscle?
A: rapid movement
Q: What is the major function of slow twitch muscle?
A: sustained movement
Q: What is the major function of the a1 receptor?
A: increase vascular smooth muscle contraction
Q: What is the major function of the a2 receptor (2)?
A: -decrease sympathetic outflow, -decrease insulin release
Q: What is the major function of the B1 receptor (5)?
A: increase HR, -inc. conntractility, -inc. renin release,-inc. lipolysis, -inc. aq. Humor formation
Q: What is the major function of the B2 receptor (3)?
A: vasodilation, bronchodilation, inc. glucagon release
Q: What is the major function of the D1 receptor?
A: relax renal vascular smooth muscle
Q: What is the major function of the D2 receptor?
A: modulate transmitter release, esp. in brain
Q: What is the major function of the H1 receptor (4)?
A: increase mucous production, -contract bronchioles, -pruritis, -pain
Q: What is the major function of the H2 receptor (4)?
A: increase gastric acid secretion
Q: What is the major function of the liver?
A: service for the other organs and tissues
Q: What is the major function of the M1 receptor?
A: CNS
Q: What is the major function of the M2 receptor?
A: decrease heart rate
Q: What is the major function of the M3 receptor?
A: increase exocrine gland secretions
Q: What is the major function of the V1 receptor?
A: increase vascular smooth muscle contraction
Q: What is the major function of the V2 receptor?
A: increase water permeability and reabsorption in the renal collecting tubules
Q: What is the major inhibitor of glyc and pyr ox?
A: citrate (FA and ketone bodies) ATP and cAMP, -acetyl CoA, NADH, ATP
Q: What is the major inhibitor of TCA?
A: ATP, long-chain acyl-coA
Q: What is the major inhibitor of cholesterol synthesis (2)?
A: cholesterol and cAMP
Q: What is the major inhibitor of glycogenesis?
A: ADP and AMP and F-2,6-bis-P
Q: What is the major metabolic pathway of fast twitch muscle?
A: glycolysis
Q: What is the major metabolic pathway of slow twitch muscle?
A: Aerobic pathways like B oxidation and TCA cycle
Q: What is the major product of fast twitch muscle?
A: lactate
Q: What is the major product of slow twitch muscle?
A: lactate
Q: What is the major regulatory enzyme of glycogenolysis?
A: glycogen synthase
Q: What is the major regulatory enzyme of lipogenesis?
A: acetyl CoA carboxylase
Q: What is the major regulatory enzyme of pentose phosphate pathway (PPP)?
A: glucose-6-P dehydrogenase
Q: What is the major regulatory enzyme of TCA?
A: citrate synthase
Q: What is the mechanism for the ETC inhibitors?
A: directly block ETC, cause decreased proton gradient
Q: What is the mechanism for the ETC uncoupler?
A: inc. membrane permeability, decreases proton gradient and increases O2 consmption
Q: What is the mechanism of ethanol hypoglycemia?
A: NADH/NAD increases in liver
A: causes diversion of pyruvate to lactate and OAA to malate
A: inhibits gluconeogenesis and thus leads to hypoglycemia
Q: What is the mnemonic for the various substrates of the TCA cycle?
A: Cindy Is Kinky So She Fornicates More Often
Q: What is the mneumonic for essential AA?
A: PriVaTe TIM HALL
Q: What is the mneumonic for major apolipoproteins?
A: A-1 Activates LCAT
A: B-100 Binds to receptor
A: C-II is a Cofactor for LPL
A: E mediates Extra (remnant) uptake
Q: What is the pneumonic for the Urea cylce substrates?
A: Ordinarily, Careless Crappers Are Also Frivolous About Urination
Q: What is urobilinogen?
A: an intestinal intermediate
A: reabsorbed to blood and excreted in urine as urobilin
Q: What other physiological side affect occurs by this hypoglycemia?
A: fatty liver seen in chronic alcoholics
Q: What rxn does pyruvate dehydrogenase catalyze?
A: pyruvate+NAD+CoA goes to acetyl-CoA +CO2+NADH
Q: What second messenger system does Gi work through?
A: adenylcyclase reduces cAMP levels and protein kinase A is reduced
Q: What second messenger system does Gq work through?
A: phospholipase C, PIP2 to IP3 and DAG
A: DAG works through protein kinase C
A: IP3 increases IC calcium ion
Q: What second messenger system does Gs work through?
A: adenylcyclase converts ATP to cAMP to phosphorylate protein kinase A
Q: What some properties of bilirubin (3)?
A: sparingly water soluble
A: toxic to CNS
A: transported by albumin
Q: What step does this enzyme work on?
A: HMG-CoA to mevalonate
Q: What suppresses glycogenesis?
A: insulin
Q: What tissues require insulin for glucose uptake?
A: adipose and skeletal muscle
Q: What type of metabolism occurs in the both (3)?
A: -gluconeogenesis, -urea cycle, heme synthesis
Q: What type of metabolism occurs in the cytoplasm (5)?
A: glycolysis, -fatty acid synthesis, -HMP shunt, -protein synthesis (RER), -steroid synthesis (SER)
Q: What type of metabolism occurs in the mitochondria (3)?
A: Beta oxidation, -Acetyl-CoA production, -Kreb's cycle
Q: When are ketone bodies formed (2)?
A: during prolonged starvation
A: diabetic ketoacidosis
Q: Where are basic AA found in high amounts?
A: in Histones that bind to negative DNA
Q: Where are cholymicrons made?
A: small intestine
Q: Where are ketone bodies made?
A: liver
Q: Where does FA degradation occur?
A: mitochondria, where it will be used
Q: Where does FA synthesis occur?
A: cytosol
Q: Where is ALA synthase found and what inhibits it?
A: mitochondria, heme
Q: Where is HDL secreted from (2)?
A: liver and small intestine
Q: Where is insulin made?
A: B cells of pancreas
Q: Where is NADPH generated?
A: is a product of HMP shunt and the malate dehydrogenase rxn
Q: Where is SAM generated?
A: From ATP and methionine
Q: Where is VLDL made?
A: liver
Q: Which ketone body is detected in urine test (1 only)?
A: acetoacetate
BIOCHEM_PROTEINS
Q: Carbon monoxide has a greater affinity for what molecule?
A: CO has 200x greater affinity for hemoglobin than for oxygen
Q: Describe the subunits for hemoglobin?
A: hemoglobin is composed of 4 polypeptide subunits (2 alpha and 2 beta)
Q: During the cycle of the sodium pump, it is __.
A: phosphorylated
Q: How are enzymes regulated?
A: 1. enzyme concentration alteration (syntesis and/or destruction)
A: 2. covalent modification (eg. phosphorylation)
A: 3. proteolytic modification (zymogen)
A: 4. allosteric regulation (eg. feedback inhibition)
A: 5. transcriptional regulation (eg. steroid hormones)
Q: How does calcium cause skeletal muscle contraction?
A: Ca2+ -> activates troponin -> moves tropomyosin -> exposes actin-bining site -> allows actin-myosin interaction
Q: How does calcium cause smooth muscle contraction?
A: Ca2+ -> binds to calmodulin because smooth muscle doesn't have troponins!
Q: How does procollagen molecules become collagen fibrils?
A: procollagen molecules cleaved at terminal regions by peptidases to become insoluble tropocollagen, which aggregates to form fibrils
A: procollagen molecules are exocytosed into extracellular space, where this process occurs
Q: How is CO2 transported from tissue to lungs?
A: - binds to amino acids in globin chain (at N-terminus), not to heme
A: - favors T form of Hb (thus promotes O2 unloading)
Q: How is collagen fibillar structure reinforced?
A: by the formation of covalent lysine-hydroxylysine crosslinks between tropocollagen molecules
Q: How is hemoglobin structure regulated?
A: increased Cl-, H+, CO2, DPG, and temperature favor T form (low affinity of O2)--shifting the dissociation curve to the right, leading to increased O2 unloading
Q: Most cells are in which cell cycle phase?
A: G0
Q: On what cellular stuctures are microtubules found?
A: flagella, cilia, mitotic spindles
Q: On which cells is phosphotidylcholine (lecithin) a major component?
A: - RBC membranes
A: - myelin
A: - bile
A: - surfactant (DPPC--dipalmitoyl phosphatidylcholine)
A: - also used in the esterification of cholesterol
Q: Only the cytoplasmic side of membrane contains what?
A: glycosylated lipids or proteins
Q: The lower the Km, the (higher/lower/remains same) the affinity
A: higher
Q: What are the 2 forms of hemoglobin?
A: - T (taut) form has low affininty for oxygen
A: - R (relaxed) form has 300x higher affinity for oxygen
A: Hb exerts positive cooperativity and negative allostery, accounting for the sigmoid-shaped O2 disassociation curve (which myoglobin doesn't have)
A: [Hint: When you're RELAXED, you do your job better (carry more O2)]
Q: What are the cell cycle phases?
A: Mitosis (Prophase-Metaphase-Anaphase-Telophase)
A: G1 (Gap or Growth)
A: S (Synthesis of DNA)
A: G2 (Gap or Growth)
A: G0 (quiescent G1 phase)
Q: What are the characteristics of a microtubule?
A: - cylindrical structure 24nm in dia and variable length
A: - helical array of polymerized dimers of alpha- and beta-tubulin (13 per circumference)
A: - each dimer has 2 GTP bound
A: - grows slowly, collapses quickly
A: - involved in slow axoplasmic transport in neurons
Q: What are the characteristics of competitive inhibitors?
A: - resemble substrates
A: - bind reversibly to active sites of enzymes
A: - high substrate concentrations overcomes effect of inhibitors
A: - Vmax remains unchanges
A: - Km increases compared to unhibited
A: [see graph & hint, p 168]
Q: What are the characteristics of noncompetitive inhibitors?
A: - doesn't resemble substrate
A: - bind to enzyme but not necessarily at active site
A: - inhibition can't be overcome by high substrate concentration
A: - Vmax decreases
A: - Km remains unchanged compared to uninhibited
A: [see graph & hint, p 168]
Q: What cell cycle phases are variable in duration?
A: G1 and G0
Q: What drugs act on microtubules?
A: - mebendazole/thiabendazole (antihelmintic)
A: - taxol (anti-breast cancer)
A: - griseofulvin (antifungal)
A: -cholchicine (anti-gout)
Q: What drugs inhibits the sodium pump?
A: - Ouabain inhibits the pump by binding to the K+ site
A: - cardiac glycosides (digoxin, digitoxin) also inhibit the pump, causing increased cardiac contractility
Q: What is methemoglobinemia?
A: blood disorder where methemoglobin, an oxidized form of hemoglobin (ferric, Fe3+) that does not bind O2 as readily. Iron in Hb is normally in a reduced state (ferrous, Fe2+)
Q: What is the difference between collagen fibril and collagen molecule?
A: fibril is made of molecules
A: collagen fibril--many staggered collagen molecules linked by lysyl oxidase
A: collagen molecule--3 collagen alpha chains, usually of Gly-x-y (x and y = pro, OH-pro, or OH-lys)
Q: What is the first step in forming collagen from prolyl and lysyl residues? Where does it occur? What nutrient does it require?
A: hydroxylation
A: endoplasmic reticulum
A: vitamin C
Q: What is the plasma membrane composition?
A: - cholesterol (~50%, promotes membrane stability)
A: - phospholipids (~50%)
A: - sphingolipids
A: -glycolipids
A: -proteins
Q: What is the sodium pump?
A: Na-K ATPase
Q: What molecules, how many of them, and in what direction are moved across the membrane by the sodium pump?
A: 3 Na go out and 2 K go in
Q: Where is the sodium pump?
A: on the membrane, with the ATP site on the cytoplasmic side of the pump
Q: Which cell cycle phase is shorter in rapidly dividing cells?
A: rapidly dividing cells have a shorter G1 phase
Q: Which cell cycle phase is usually shortest?
A: mitosis
BIOCHEM_VITAMINS
Q: Arthralgia's, fatigue, headaches, skin changes, sore throat, alopecia are symptoms foundin what vitamin deficiency
A: Vit A (Retinal)
Q: How does sarcoidosis cause hypercalcemia?
A: in sarcoid, epitheliod macrophages convert vitamin D into it's active form leading to increased absorption of calcium
Q: How many ATP are made from Niacin
A: Niacin=NAD
A: niacin is B3=3 ATP
Q: What are the characteristic findings seen in Riboflavin deficiencies
A: Riboflavin is B2
A: 2 C's=cheilosis and Corneal vascularization and also Angular stomatitis
Q: What are the fat soluble vitamins
A: D,A,K,E
Q: What are the findings in Vit D excess?
A: Hypercalcemia, loss of appetite, stupor
Q: What are the possible causes of hypercalcemia?
A: 1. Vit D intoxication
A: 2. Malignancy
A: 3. Hyperparathyroidism
A: 4. Milk-alkali syndrome
A: 5. Sarcoidosis
A: 6. Paget's disease of bone
Q: What are the signs and symptoms of vit B12 deficiency?
A: 1. Macrocytic megaloblastic anemia
A: 2. Neurologic symptoms-optic neuropathy, subacute combined degeneration
A: 3.glossitis
Q: What are the signs of Biotin deficiency and what are possilble causes?
A: dermatitis, enteritis
A: antiobiotic use and ingestion of raw eggs
Q: What are the signs of Folate deficiency?
A: Macrocytic megaloblastic anemia
A: sprue
Q: What are the symptoms in Vit B5 deficiency
A: dermatitis, enterititis, alopecia, adrenal insufficiency
Q: What are the symptoms of Pellagra
A: 3 D's Diarrhea, Dermatitis, Dementia, and also Beefy glossitis
Q: What are the usual causes of Vit B12 deficiency?
A: 1. Malabsorption- Sprue, enteritis, Diphyllobthrium latum (Dr. Lohr's fish tapeworm)
A: 2.lack of intrinsic factor (pernicious anemia)
A: 3. Absence of the terminal ileum- Crohn's disease or surgery
Q: What are the water soluble vitamins
A: B complex vitamins (B1,2,3,5,6,12), Vit C, Biotin, Folate
Q: What can induce pyridoxine deficiency? Symptoms?
A: INH and oral contraceptives
A: convulsion, hyperirritability
Q: What clotting factors are Vit K dependent and what anti-clotting drug acts as a Vit K antagonist?
A: Factors II, VII, IX, X and Protein C and S
A: Warfarin
Q: what disease is characterized by polyneuritis, cardiac pathology and edema and what is the cause
A: Beriberi (Ber1BerI), due to Vit B1 deficiency
Q: What diseases conditions are caused by Vitamin D deficiency?
A: Rickets in kids
A: Osteomalacia in adults
A: hypocalcemic tetany
Q: What diseases is caused by Vit C deficiency and what are the findings?
A: Scurvy
A: swollen gums, bruising, anemia, poor wound healing
Q: What is B12 used for in the body?
A: Cofactor for homocysteine methylation and methylmalonyl-CoA handling
Q: What is Niacin's function in the body and from what can it be derived
A: part of NAD, NADP and is derived from tryptophan
Q: What is the active form of Vitamin D?
A: 1,25 (OH)2 D3 = active form
Q: What is the alternate name of Vit B3, problems in deficiency, common cause of defieciency
A: niacin
A: Pellagra
A: Hartnup disease, malignant carcinoid syndrome, and INH
Q: What is the alternate name of vitamin B1 and what are the characteristic diseases of it's deficiency
A: Beriberi and Wernicke-Korsakoff syndrome
Q: What is the folic acid precursor in bacteria and what antibiotics exploit this fact?
A: PABA is the precursor
A: sulfa drugs and dapsone are PABA analogs
Q: What is the form of vitamin D consumed in milk?
A: D2 = ergocalciferol
Q: What is the form of Vitamin D found in sun-exposed skin?
A: D3 = cholecalciferol
Q: What is the function and alternate name of Vit. B2
A: cofactor in oxidation and reduction (FAD,FMN)
A: RiboFlavin
Q: What is the function of Biotin?
A: Cofactor for carboxylations
A: 1. Pyruvate to oxaloacetate
A: 2. Acetyl-CoA to malonyl Co-A
A: 3. Prprionyl-CoA to methylmalonyl-CoA
Q: What is the function of folic acid?
A: coenzyme for 1-carbon transfer;methylation reactions
A: important for the synthesis of nitrogenous bases in DNA and RNA
Q: What is the function of Vit A, it's alternate name, and symptoms in deficiency
A: visual pigments (retinal)
A: retinol
A: night blindness and dry skin
Q: What is the function of Vit B1
A: it becomes Thiamine Pyrophosphate (TPP) and is used in:
A: oxidative decarboxylation of Alpha-keto acids (pyruvate, Alpha-ketoglutarate
A: cofactor for tranketolase in the HMP shunt
Q: What is the function of Vit B6
A: B6 (pyridoxine) is converted to pyridoxal phosphate
A: a cofactore in transamination reactions (ALT & AST), decarboxylation, and trans-sulfuration
Q: What is the function of Vit E?
A: antioxidant; especially in Erythrocytes where it protects them from hemolysis
A: Vit E is for Erythrocytes
Q: What is the function of vitamin C?
A: 1. Cross linking of collagen-hydroxylation of proline and lysine in collagen synthesis
A: keeping iron in the Fe2+ reduced state making it more absorbable
A: 3. Cofactor for coverting dopamine to norepinephrine
Q: What is the function of Vitamin D?
A: increase intestinal absorption of Calcium and phosphate
Q: What is the function of Vitamin K?
A: catalyzes gamma-carboxylation of glutamic acid residues on various proteins concerned with clotting.
Q: What is the most common vitamin deficiency in the United States?
A: Foilic Acid
Q: What is the rule of 2's for Vit B2
A: 2 F's, 2C's and 2ATP
A: 2 F's=FAD&FMN
A: 2 C's = signs of deficiency cheilosis and corneal vascularization
A: oxidation of FADH2 leads to 2 ATP
Q: What is the sotrage form of Vitamin D?
A: 25-OH D3
Q: What is the source of Vit B12 and what is B12's other name
A: found only in animal products
A: cobalamin
Q: What is vit B5's function and alternate name
A: constituent of CoA, part of fatty acid synthase. Cofactor for acyl transfers
A: Pantothenate (Pantothen-A is in Co-A)
Q: What manifestation is specific to wet beriberi?
A: high output cardiac failure (dilated cardiomyopathy)
Q: What molecule in egg white binds up Biotin and causes deficiency
A: Avidin
Q: What problems do you see in Vit K deficiency?
A: