HY Biochemistry :)) - chebli - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 1 (https://www.usmleforum.com/forumdisplay.php?fid=2) +--- Thread: HY Biochemistry :)) - chebli (/showthread.php?tid=246982) |
HY Biochemistry :)) - chebli - ArchivalUser - 11-27-2007 Characteristic Disease 1 phenotype of cretinism pot-bellied, severely retarded, pale child with glossitis and puffy face 2 gene and chromosome associated with bilateral schwannomas NF-2, chromosome 22q 3 chromosome associated with retinoblastoma and osteosarcoma 13q 4 p53 is located on this chromosome 17q 5 gene and chromosome associated with colorectal cancers APC, chromosome 5q 6 lack of secondary sex characteristics in a male, mild mental retardation Klinefelter's 7 genetics of Klinefelters nondisjunction of sex chromosomes 8 another name for type 2a lipidemia familial hypercholesterolemia 9 patients with sickle cell often get gallstones made of calcium bilirubinate 10 genetics of sporadic cases of Duchenne's MD recombination --> frameshift mutation --> untranslatable mRNA 11 trisomy with polydactyly Trisomy 13 (Patau) 12 the GLUT in fat, skeletal mm, and heart GLUT 4 13 the GLUT found in liver, β cells of pancreas, and basolateral surface of small bowel GLUT 2 14 function of pyruvate carboxylase pyruvate + --> OAA + 15 activator of pyruvate carboxylase acetyl CoA 16 inheritance of Huntington's autosomal dominant 17 amenorrhea, short stature, aortic coarctation Turner's (XO) 18 child normal at birth, but with progressive deafness, blindness, diminished responsiveness, and seizures Tay-Sachs 19 musty body odor + mental retardation PKU 20 what substance accumulates in Tay-Sachs? ganglioside GM2 21 deficiency of lipoprotein lipase causes ___ to accumulate after a high-fat meal chylomicrons 22 deficiency of lipoprotein lipase causes ___ to accumulate after a high-CHO meal VLDL 23 what are p and q in the Hardy-Weinburg equation? p = freq of having the dominant gene, q = freq of having the recessive gene 24 q squared in words frequency of people with the characteristic represented by q 25 significance of 2pq frequency of heterozygosity, or carrier frequency 26 Hardy-Weinberg equations p+q=1, (p+q)^2=1 27 hepatomegaly and hypoglycemia suggest what general category of diseases? glycogen storage disease 28 two diseases that occur at high frequency in Ashkenazic Jews Tay-Sachs and Gaucher's 29 high-pitched cat-like cry w/ VSD, mental retardation, microcephaly, and slanted palpebral fissures cri-du-chat syndrome 30 glutamine, glycine, and THF are used in the synthesis of which nucleotides? purines (A, G) 31 multiple phenotypic features seen in a patient with a single gene defect pleiotropy 32 purine salvage is affected by what dz? Lesch-Nyhan 33 CHO chains that will be transferred to a protein are synthesized on dolichol 34 differential transcriptional activity of genes inherited by mom vs dad imprinting 35 lactic acid is the product of what process? anaerobic glycolysis 36 product of β oxidation of fatty acids acetyl CoA 37 products of pentose phosphate shunt (HMP) ribose-5-phosphate and NADPH 38 hepatomegaly with progressive neurologic dysfunction suggests what general category of disease? lipid storage disease 39 Neimann-Pick results from a deficiency in sphingomyelinase 40 corneal opacities, neuropathy, and violacious nodules on skin; transmission is X-linked Fabry's disease 41 Name some X-linked diseases Fabry's, Hunter's, DMD, BMD, G6PD, Lesch-Nyhan, ocular albinism 42 onset of preeclampsia before the 20th week of pregnancy hydatidiform mole 43 fasting hypoglycemia and hypoketosis together suggest what general category of disease? deficiency in fatty acid oxidation 44 role of LCAD 1st step in fatty acid oxidation 45 what substance accumulates in LCAD deficiency? carnitine esters 46 activity of what heart enzyme should be increased in cocaine toxicity? PFK-1 (cocaine --> vasoconstriction of epicardial aa --> glycolysis --> increased PFK-1) 47 what causes the mutations of DMD and BMD? insertions or deletions 48 mature fetal tissue containing Barr bodies suggests Klinefelter's 49 Barr bodies are seen in anyone with 2 X chromosomes (including normal XX females) 50 why does the body need carnitine? it transports fatty acids across the inner mitochondrial membrane for oxidation 51 clinical features of fructosuria none - asx 52 Clinitest measures ___ in urine reducing sugars (glucose, fructose, galactose) 53 in autosomal dominant transmission, the first occurrence in a family is usually the result of new mutation in mom or dad transferred to kid by gamete 54 genetic mutation in acondroplasia fibroblast growth factor 3 (involved in cell signalling) 55 normal cells have __N DNA 2N 56 cells in metaphase of mitosis have __N DNA and __ chromosomes 2N DNA, 46 chromosomes 57 there are 92 chromosomes in which two stages of mitosis? anaphase and telophase 58 gene flow defined exchange of genes among previously-separated populations 59 defined as random fluctuations of gene frequencies among small populations genetic drift 60 aplastic crisis in sickle cell is also called hematologic crisis 61 causes of aplastic crisis in sickle cell patients parvovirus B19 and folate deficiency 62 name a similarity between thrombin and chymotrypsin. serine proteases 63 name some other serine proteases. thrombin, prothrombin, elastase, plasminogen 64 how do steroids work their magic? bind to intracellular receptors, translocate to nucleus, and alter protein synthesis 65 hCG is in the same family as what 3 other hormones? TSH, FSH, and LH 66 transmission of hemophilia X-linked 67 incidence of G6PD deficiency in African-American males 10% 68 G6PD is the committed step of hexose monophosphate shunt 69 without G6PD, ____ is lacking NADPH 70 transmission of G6PD deficiency X-linked 71 transmission of the MEN syndromes autosomal dominant 72 transmission of hypertrophic cardiomyopathy autosomal dominant 73 transmission of G6PD deficiency X-linked 74 transmission of pyruvate kinase deficiency autosomal recessive 75 on what chromosome is the deficiency that causes DiGeorge syndrome? 22 76 paternity testing is based on genetic allotypes 77 laboratory test used to determine if a person has Ab to a particular virus ELISA 78 name the most appropriate lab test to use to determine if a patient with Rb has a heritable form or a sporadic form PCR 79 carnitine acyltransferase II is located on the . inner mito membrane 80 fatty acyl-CoA synthetases are located on the. outer mito membrane 81 the triple helix structure of collagen is initially formed in the rER 82 cleavage of propeptides and cross-linking of strands of collagen occurs extracellularly 83 three common causes for spontaneous abortions Trisomy 16, triploidy, and Turner's (46,X0) 84 transmission pattern of galactosemia autosomal dominant 85 If nondisjunction at chromosome 21 occurs during meiosis I, the baby will have genotype both of the chromosomes from the parent w/ nondisjunction, and one chromosome from the normal parent (i.e. ABC) 86 If nondisjunction at chromosome 21 occurs during meiosis II, the baby will have genotype. two identical chromosomes from the parent w/ nondisjunction, and one chromosome from the normal parent (i.e. AAC) 87 define this occurrence: "a single homologous chromosome fails to separate during the first meiotic division" nondisjunction 88 what is the difference between trisomy and triploidy? trisomy = one of the gametes has 24 chromosomes, for a total of 47; triploidy = 69 chromosomes resulting from two sperm + 1 egg 89 define uniploidly the state of having 23 chromosomes (normal) 90 what is the difference between balanced and unbalanced translocations? both are non-homologous chromosomes that exchange genetic material; balanced = no loss or gain of critical material; nonbalanced = loss or gain of critical material 91 the effect of citrate on PFK-1 allosteric inhibitor (when TCA cycle slows down, so must glycolysis) 92 name a few molecules that form vesicles in water amphipathic molecules with hydrophobic tails - phospholipids and sphingolipids 93 name a few molecules that form droplets in water hydrophobic, nonpolar molecules - cholesterol esters and TGs 94 what happens to cholesterol in aqueous solution? it preciptates 95 refers to a failure of paired chromosomes to separate and go to different daughter cells (during mitosis or meiosis) nondisjunction 96 the protein that carries vesicles from the soma of a nerve cell to the end of the dendrite (anterograde transport) kinesin 97 the protein that carries vesicles in a retrograde direction dynein 98 can heavy irradiation of sex gametes cause Down's syndrome? no - not been proven 99 effect of pyruvate on pyruvate dehydrogenase enzyme activity increases PDH activity (increased pyruvate means increased need for TCA activity) 100 other substances that tend to excite PDH high ADP, high intracellular Ca, decreased ACoA (note these all happen during exercise) 101 what is important about the 3' end of a eukaryotic intron? invariant AG, called the "splice acceptor site" 102 what is important about the 5' end of a eukaryotic intron? invariant GT, called the "splice donor site" 103 proteins that make up gap junctions connexins 104 protein that initiates the formation of zona occludens and desomsomes E-cadherin 105 where in the cell is desmoglein? desmosomes 106 the incidence of an x-linked dz in a male population is equal to gene frequency in the population 107 to determine if a person is a carried of the CF mutation, what lab test should be done? PCR and gene sequencing for deltaF508 108 define heteroplasmy presence of normal AND mutated mitochondrial DNA in one individual 109 a deficiency in clathrin would produce what cellular problems? endocytosis, delivery of lysosomal enzymes to the lysosomes from the Golgi 110 the Go phase of the cell cycle begins during what phase? G1 111 name the phases of the cell cycle (in order, please) G1 > S > G2 > M 112 Hirschprung's disease results from what embryologic deficit? failure of neural crest cells to end up there 113 why are female carriers of X-linked disorders often mildly affected? X chromosomes are inactivated, and most of the mutant ones are inactive 114 the four required enzymes in gluconeogenesis pyruvate carboxylase, fructose 1,6 bisphosphatase, PEP carboxykinase, glucose 6-phosphatase (Pathway Produces Fresh Glu) 115 enzyme deficiency in Pompe's disease alpha glucosidase 116 transmission of Wiscott-Aldrich X-linked 117 does pinocytosis require clathrin? no (only receptor-mediated endocytosis) 118 average life span of a patient with Edward's trisomy 2-3 months 119 melanin is made from what aa? tyrosine 120 patients with tyrosinase deficiency are susceptible to what types of cancer? skin cancers 121 neonate with IUGR and genetic abnormality of the placenta only confined placental mosaicism 122 can ACoA be used to make glucose? NO NO NO NO NO 123 in dieting obese individuals who take in little CHO, where does the glucose come from? (hint: engogenous pathway) glycerol > gluconeogenesis 124 if uracil is high, what urea cycle enzyme is working properly? carbamoyl phosphate 125 dietary deficiency in folate is usually due to (2) overcooking or old foods 126 the genetic defect in Angelman syndrome deletion of q12 on maternal chromosome 15 127 enzyme deficiency in albinism tyrosine hydroxylase 128 the splice acceptor site is located 3' end of the intron 129 the 5' end of an intron has the splice donor site 130 what charge do NH3 groups have at pH=7? (+) charge 131 two basic amino acids lys, arg 132 two acidic amino acids glu, asp 133 what type of receptor is EGF-R? tyrosine kinase 134 nucleotide made from excess carbamoyl phosphate uracil 135 high amounts of glutamine may indicate a deficiency in what urea cycle enzyme? ornithine transcarbamoylase 136 during RNA synthesis, how many ATP equivalents are used to elongate the chain by 1 aa? 4 (tRNA activation, gripping of tRNA, formation of peptide bond, tranlocation) 137 high homocystine and methylmalonate in blood indicate a deficiency in Vitamin B 12 138 orotic aciduria is a genetic defect in which pathway? pyrimidine metabolism 139 aspartate aminotransferase catalyzes the reaction . OAA + > apartate + 140 aspartate aminotransferase requires what cofactor? pyridoxine (vitamin B6) - required by all transaminases 141 methylmalonate is elevated in (B12/folate) and NOT elevated in (B12/folate) deficiency methylmalonate is elevated in B12 deficiency ONLY 142 low transketolase activity is typical of what vitamin deficiencies? folate and B12 143 define the heritability index in words the percentage of a disease for which genes are responsible 144 define the heritability index in numbers/symbols HI = (MZ-DZ)/(100-MZ) 145 on a tree, how to tell the difference between mitochondrial and X-linked recessive X-linked only affects boys; mitochondrial affects boys and girls 146 Na primarily moves between blood and interstitium via intercellular junctions 147 which lipids are dependent on an essential FA for synthesis? eicosanoids (i.e. PGs) 148 what enzyme releases NH# for use by carbamoyl phosphate? glutamate DH 149 vitamin used by transketolase Vitamin B1 (thiamine) 150 deficiency of all enzymes in what process can lead to hemolytic anemia? glycolysis 151 two glycolysis enzymes that produce NADH 6-phosphogluconate DH and G6PDH 152 what is the role of adenosine deaminase? catalyzes adenosine > inosine 153 when NADH is low and ACoA is high, what is the fate of pyruvate? goes to OAA by pyruvate carboxylase 154 what intermediate of glycolysis is required for fat storage DHAP 155 from where do the NH3 groups in purines come? glutamine donor 156 5 ingredients in purine synthesis CO2, glycine, glutamine, aspartate, formate 157 deamination of cytosine produces uracil 158 Cori's disease is a deficiency of debranching enzyme 159 degraded first in an apoptotic cell is 10 nm DNA fibers ("most unwound") 160 how to detect a hemoglobinopathy from amniotic fluid Southern blot 161 activator of ACoA carboxylase for the purpose of fatty acid synthesis citrate 162 restriction sites are usually made up of palindromes 163 what vitamin deficiency could produce hypertyrosinemia? vitamin C deficiency 164 what shuttle is used to shuttle fatty acids into the mitochondrion for oxidation? carnitine shuttle 165 citrate directly affects which enzyme of glycolysis? PFK-1 (- allosteric inhibitor) 166 differences in phenotype based upon whether the gene came from Mom or Dad is called . imprinting 167 what is the role of clathrin in the cell? receptor-mediated endocytosis, budding from the Golgi (headed to lysosomes/endosomes) 168 incidence in terms of Hardy-Weinberg genetics q^2 169 the carrier frequency is approximated with 2q 170 (+)-directed microtubule motor proteins; take stuff from the soma to the axon ends kinesin 171 difference between kinesin and dynein dynein is (-)-directed; takes stuff toward the cell body 172 abnormal ____ ____ can produce tripolar mitoses mitotic spindles 173 what is a chiasma? when two homologous chromosomes align to exchange genetic material 174 CFTR is located on what chromosome? 7 175 # of acetoacetate molecules that can be produced from oxidation of a C11 fatty acid 2 176 two enzymes that may be deficiency in PKU Phe hydroxylase or dihydrobioptein reductase 177 technically an IMINO acid proline 178 what aa should be restricted in the diet of a patient with maple syrup urine dz? ile, leu, val 179 what aa is used in the biosynthesis of purines? glutamine 180 O-linked glycosylation of proteins occurs in the Golgi 181 porphyrins are synthesized from glycine + Succinyl CoA 182 how many ATP are made from complete oxidation of one glucose to Co2 + H2O? 38 183 niacin is required in which TCA cycle reaction? isocitrate DH 184 von Gierke's disease results from lack of glucose-6-phosphatase (autosomal recessive) 185 succinate DH is found on the inner mito membrane 186 most common cause of hereditary hyperammonemia deficiency of carbamoyl phosphate synthetase I 187 treatment of DNA with micrococcal nuclease will result in DNA bound to octamer of histones 188 muscle uses ___ for energy during starvation fatty acids 189 during starvation, glucose is "reserved" for what body system? CNS 190 a patient with Down's phenotype but 46 chromosomes on karyotype analysis probably had what occur to their chromosomes? Robertsonian translocation 191 a mixture of cells with 46 or 47 chromosomes on karyotypic analysis indicates mosaicism (occurs in 1% of Down's patients) 0 - ArchivalUser - 11-27-2007 ) 0 - ArchivalUser - 11-27-2007 ) 0 - ArchivalUser - 11-27-2007 ) 0 - ArchivalUser - 11-29-2007 Some fellows still looking for these notes, so I thought of bringing it back to the surface. |