Question 1

The key enzyme in regulation of glycogen degradation is

Accepted Answer

A)  glycogen phosphatase. 
B)  glycogen phosphorylase. 
C)  glucose 1-phosphate synthase. 
D)  glycogen kinase. 
E)  None of the answers is correct. 
A)  glycogen phosphatase. 
B)  glycogen phosphorylase. 
C)  glucose 1-phosphate synthase. 
D)  glycogen kinase. 
E)  None of the answers is correct.

Question 2

Phosphorylase requires the coenzyme ______________________ for activity.

Accepted Answer

The answer of Phosphorylase requires the coenzyme ______________________ for activity....

Question 3

______________ markedly stimulates glycogen breakdown in muscle by initiating a cAMP signal-transduction cascade.

Accepted Answer

Epinephrin

Question 4

By what mechanism is phosphorylase kinase activated by Ca2+ levels of 1 μM?

Accepted Answer

The δ subunit of phosphorylase kinase is

Question 5

Which of the following occur after a carbohydrate-rich meal?

Accepted Answer

A)  Blood-glucose levels increase leading to glycogen storage in the liver. 
B)  Blood-glucose levels increase leading to glycogen storage in the muscle. 
C)  Glucose uptake from the blood increases as a result of the action of insulin. 
D)  Glucagon is absent. 
E)  All of the answers are correct. 
A)  Blood-glucose levels increase leading to glycogen storage in the liver. 
B)  Blood-glucose levels increase leading to glycogen storage in the muscle. 
C)  Glucose uptake from the blood increases as a result of the action of insulin. 
D)  Glucagon is absent. 
E)  All of the answers are correct.

Question 6

Why must glycogen control be manifested differently in muscle and liver?

Accepted Answer

It is because the muscle maint

Question 7

Which of the following is a major site of glycogen storage?

Accepted Answer

A)  adipose tissue 
B)  liver 
C)  pancreas 
D)  kidney 
E)  All of the answers are correct. 
A)  adipose tissue 
B)  liver 
C)  pancreas 
D)  kidney 
E)  All of the answers are correct.

Question 8

What physiological conditions render phosphorylase b less active?

Accepted Answer

A)  High ATP, AMP, and glucose 6-phosphate levels 
B)  High ATP and low calcium ion levels 
C)  High ATP and glucose 6-phosphate levels 
D)  High AMP and low ATP levels 
E)  None of the answers is correct. 
A)  High ATP, AMP, and glucose 6-phosphate levels 
B)  High ATP and low calcium ion levels 
C)  High ATP and glucose 6-phosphate levels 
D)  High AMP and low ATP levels 
E)  None of the answers is correct.

Question 9

The key regulatory enzyme that primarily controls the rate of glycogen synthesis is

Accepted Answer

A)  glycogen synthase phosphorylase. 
B)  glycogen synthase. 
C)  glycogen synthase kinase. 
D)  protein phosphatase-1. 
E)  None of the answers is correct. 
A)  glycogen synthase phosphorylase. 
B)  glycogen synthase. 
C)  glycogen synthase kinase. 
D)  protein phosphatase-1. 
E)  None of the answers is correct.

Question 10

In muscle,the first event in the breakdown of glycogen due to binding of a hormone is _____.

Accepted Answer

A)  cytoplasmic cAMP levels rise 
B)  protein kinase A phosphorylates phosphorylase kinase 
C)  adenylate cyclase is activated 
D)  protein kinase A is activated 
E)  activation of a G protein 
A)  cytoplasmic cAMP levels rise 
B)  protein kinase A phosphorylates phosphorylase kinase 
C)  adenylate cyclase is activated 
D)  protein kinase A is activated 
E)  activation of a G protein

Exam 21: Glycogen Metabolism

The key enzyme in regulation of glycogen degradation is

Phosphorylase requires the coenzyme ______________________ for activity.

______________ markedly stimulates glycogen breakdown in muscle by initiating a cAMP signal-transduction cascade.

By what mechanism is phosphorylase kinase activated by Ca2+ levels of 1 μM?

Which of the following occur after a carbohydrate-rich meal?

Why must glycogen control be manifested differently in muscle and liver?

Which of the following is a major site of glycogen storage?

What physiological conditions render phosphorylase b less active?

The key regulatory enzyme that primarily controls the rate of glycogen synthesis is

In muscle,the first event in the breakdown of glycogen due to binding of a hormone is _____.

Biochemistry: An Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

Oxidative Phosphorylation

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, repair, and Recombination

RNA Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

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By what mechanism is phosphorylase kinase activated by Ca²⁺ levels of 1 μM?