CHE 4342 glycogen synthesis Exam Questions and Answers Fully Solved Latest Version 2025-
2026
Where does glycogen synthesis occur? - Answers In the liver and muscles
From what end of glycogen is energy released from? - Answers The non reducing end alpha (1
->4)
What is significant about adding a phosphate to glycogen and creating G1P - Answers It is
highly exergonic
Why are there lots of branches on glycogen - Answers so there are many non-reducing ends
What is the EC classification of glycogen phosphorylase? - Answers 2
What cofactor is needed to break down glycogen? - Answers P5P, PLP pyridoxal-5-phosphate,
vitamin B6
What kind of curve occurs when an enzyme has allosteric regulation? - Answers sigmoidal
What kind of bond connects lysine to PLP - Answers covalent
What is PLP used for in glycogen phosphorylase reaction - Answers It is used in general acid
catalysis
What is significant about the oxonium in the glycogen phosphorylase mechanism - Answers it is
an unstable half chair confirmation
When the lysozyme reacts with the half chair in the glycogen phosphorylase mechanism what
does it form - Answers a general base
What is the name of the inhibitor for glycogen phosphorylase and what does it resemble? -
Answers 1,5-gluconolacetone, it resembles the lactone/transition state
What drives the reaction of glycogenolysis - Answers inorganic phosphate
What does phosphoglucomutase do? - Answers It converts G1P to G6P (EC:5)
What does UDP-glucose pyrophosphorylase do? - Answers It converts G1P to UDP-glucose, it
does a phosphoanhydride exchange
How does the glycogen branching enzyme work? - Answers A 7 residue piece is removed from
residue 6 and is transferred to a residue 4 down from original branch
What is unique about glycogen - Answers It is not just a carbohydrate it also has a protein core
called glycogenin
Glycogenin has what amino acid that acts as the anchor for the reducing ends - Answers
, tyrosine
How many UDP glucose molecules are added to each tyrosine - Answers 8
What does the enzyme fructose-1,6-bisphosphate do - Answers F16BP to F6P
What are the three hormones in control of carbohydrate metabolism - Answers Epinephrine,
glucagon, and insulin
Where is epinephrine located - Answers adrenal cells and muscle
Where is glucagon located - Answers alpha cells of pancreas
Where is insulin located - Answers pancreatic beta cells
Where are catecholamines produces - Answers adrenal medulla
What is the target of catecholamines - Answers alpha and beta adrenergic receptors
What amino acids are epinephrine and norepinephrine made from - Answers tyrosine
What are inactive precursors of enzymes called - Answers zymogens
What are zymogens - Answers enzymes synthesized with an extra stretch of protein that blocks
the active site and prevents substrate binding (inactive enzyme)
How are proteases are often synthesized - Answers zymogens
How are zymogens are converted to the active form by - Answers proteolysis by a protease
How many polypeptide amino acid residues are on glucagon - Answers 29 amino acid
What is glucagon called when it is first made and what is unique about this form - Answers
proglucagon and it is made in the inactive form and then activated as needed.
What cells secrete the insulin polypeptide - Answers the beta cells of the islets of langerhans of
pancreas
How is insulin stored - Answers as a hexamer (more stable) and as proinsulin
What is unique about the active form of insulin - Answers it has a A chain and a B chain
Insulin is considered the main _________ ________ of the body - Answers anabolic hormone
What does insulin do to glycogen - Answers It stimulates glycogen synthesis and inhibits
glycogen breakdown
What does glucagon do to glycogen - Answers it stimulates the breakdown of glycogen
2026
Where does glycogen synthesis occur? - Answers In the liver and muscles
From what end of glycogen is energy released from? - Answers The non reducing end alpha (1
->4)
What is significant about adding a phosphate to glycogen and creating G1P - Answers It is
highly exergonic
Why are there lots of branches on glycogen - Answers so there are many non-reducing ends
What is the EC classification of glycogen phosphorylase? - Answers 2
What cofactor is needed to break down glycogen? - Answers P5P, PLP pyridoxal-5-phosphate,
vitamin B6
What kind of curve occurs when an enzyme has allosteric regulation? - Answers sigmoidal
What kind of bond connects lysine to PLP - Answers covalent
What is PLP used for in glycogen phosphorylase reaction - Answers It is used in general acid
catalysis
What is significant about the oxonium in the glycogen phosphorylase mechanism - Answers it is
an unstable half chair confirmation
When the lysozyme reacts with the half chair in the glycogen phosphorylase mechanism what
does it form - Answers a general base
What is the name of the inhibitor for glycogen phosphorylase and what does it resemble? -
Answers 1,5-gluconolacetone, it resembles the lactone/transition state
What drives the reaction of glycogenolysis - Answers inorganic phosphate
What does phosphoglucomutase do? - Answers It converts G1P to G6P (EC:5)
What does UDP-glucose pyrophosphorylase do? - Answers It converts G1P to UDP-glucose, it
does a phosphoanhydride exchange
How does the glycogen branching enzyme work? - Answers A 7 residue piece is removed from
residue 6 and is transferred to a residue 4 down from original branch
What is unique about glycogen - Answers It is not just a carbohydrate it also has a protein core
called glycogenin
Glycogenin has what amino acid that acts as the anchor for the reducing ends - Answers
, tyrosine
How many UDP glucose molecules are added to each tyrosine - Answers 8
What does the enzyme fructose-1,6-bisphosphate do - Answers F16BP to F6P
What are the three hormones in control of carbohydrate metabolism - Answers Epinephrine,
glucagon, and insulin
Where is epinephrine located - Answers adrenal cells and muscle
Where is glucagon located - Answers alpha cells of pancreas
Where is insulin located - Answers pancreatic beta cells
Where are catecholamines produces - Answers adrenal medulla
What is the target of catecholamines - Answers alpha and beta adrenergic receptors
What amino acids are epinephrine and norepinephrine made from - Answers tyrosine
What are inactive precursors of enzymes called - Answers zymogens
What are zymogens - Answers enzymes synthesized with an extra stretch of protein that blocks
the active site and prevents substrate binding (inactive enzyme)
How are proteases are often synthesized - Answers zymogens
How are zymogens are converted to the active form by - Answers proteolysis by a protease
How many polypeptide amino acid residues are on glucagon - Answers 29 amino acid
What is glucagon called when it is first made and what is unique about this form - Answers
proglucagon and it is made in the inactive form and then activated as needed.
What cells secrete the insulin polypeptide - Answers the beta cells of the islets of langerhans of
pancreas
How is insulin stored - Answers as a hexamer (more stable) and as proinsulin
What is unique about the active form of insulin - Answers it has a A chain and a B chain
Insulin is considered the main _________ ________ of the body - Answers anabolic hormone
What does insulin do to glycogen - Answers It stimulates glycogen synthesis and inhibits
glycogen breakdown
What does glucagon do to glycogen - Answers it stimulates the breakdown of glycogen
