glucagon - zkadhem

[ArchivalUser]

Which of the following enzymes is stimulated by glucagon?
A. Acetyl-CoA carboxylase
B. Glycogen phosphorylase
C. Glycogen synthase
D. HMG-CoA reductase
E. Pyruvate kinase

[ArchivalUser]

b..

[ArchivalUser]

It is not C beacsue GLYCOGEN SYNTATASE IS STIMULATE BY insulin for Glycogen Syntesis.


Epinephrine and Glucogen stimulate adenyl cyclase to increase cAMP levels and activate PKA Protein Kinase A -phosphorlylate glycogen syntatase a (active ) to from glycogen syntatase b ( inactive form ) an dTURN OFF glycogen synhesis.Furtheremore, phosphorylase kinase turn on glycogenolysis by phosphorylating glycogen phoshorylas eb (inactive ) to form gflase a (active )
So answer in this question is EEEEEEEEEEEEEEE

[ArchivalUser]

I need to finish this explanation : Glycogen phosphorilase breaks down glycogen to glucose -ai phosphate an dthe debranching enzymme remove the branches.Glycogenolysis is stimulated by EPI, GLUCAGON, CALCIUYM and AMP.
Sp Enzym ephosphororylatioon sttaes determine if glycogenolysis is ON or OFF .
Snd with the previous explanation what is teh ANSWER E or B ?

[ArchivalUser]

Glucagon Represses synthesis of Pyruvate kinase the last enzyme in the glycolytic pathway

[ArchivalUser]

bbb

[ArchivalUser]

Acetyl Coa carboxylase is activated by citrate,insulin


glycogen phosphorylase by glucagon,epinephrine,AMP

Glycogen synthase by insulin,ATP ,glucose

HMG coA reductase by insulin

pyruvate kinase ADP,pfk--2

[ArchivalUser]

Explanation:
The correct answer is B. Before you started analyzing all of the answer choices you should have
reminded yourself that glucagon increases serum glucose. So an enzyme stimulated by glucagon might
be involved in either the breakdown of glycogen to glucose (glycogenolysis) or in the creation of
glucose from noncarbohydrate precursors (gluconeogenesis). Glycogen phosphorylase catalyzes the
first step in glycogenolysis; it makes sense that it would be stimulated by glucagon.
Acetyl-CoA carboxylase (choice A) catalyzes the first step in fatty acid synthesis, an anabolic
process that would be stimulated by insulin, not glucagon.
As its name implies, glycogen synthase (choice C) is involved in the synthesis of glycogen. Glucagon
(and epinephrine) stimulate the phosphorylation and inactivation of glycogen synthase.
HMG-CoA reductase (choice D) is the key enzyme involved in the synthesis of cholesterol. Since this
is an anabolic process that occurs in the well-fed state, you would expect it to be stimulated by
insulin and inhibited by glucagon (which it is).
Pyruvate kinase (choice E) catalyzes the last reaction of glycolysis. You would expect it to be
inhibited by glucagon (thus decreasing the amount of glucose consumption). Glucagon promotes the
phosphorylation of pyruvate kinase, which renders it inactive.