Question 1

Unlike liver tissue, muscle and some other tissues differ in regulation of glycogen metabolism because

Accepted Answer

A)  the enzymes are different. 
B)  there is no effect of glucagon. 
C)  there is no effect of insulin. 
D)  inhibitor-1 controls protein phosphatase-1. 
E)  there is no role for cyclic AMP. 
A)  the enzymes are different. 
B)  there is no effect of glucagon. 
C)  there is no effect of insulin. 
D)  inhibitor-1 controls protein phosphatase-1. 
E)  there is no role for cyclic AMP.

Question 2

Glycogen phosphorylaseacts on the non-reducing ends of glycogen.

Accepted Answer

A) True 
 B)False

Question 3

Which statement is true about the reaction catalyzed by glycogen synthase?

Accepted Answer

A)  It polymerizes free glucose to glycogen in the liver. 
B)  It requires UTP-glucose for chain lengthening. 
C)  It can both lengthen glycogen chains as well as form new branches. 
D)  It requires a primer of four to eight linked glucose residues. 
A)  It polymerizes free glucose to glycogen in the liver. 
B)  It requires UTP-glucose for chain lengthening. 
C)  It can both lengthen glycogen chains as well as form new branches. 
D)  It requires a primer of four to eight linked glucose residues.

Question 4

A substrate cycle in a metabolic pathway .

Accepted Answer

A)  is a good point for regulation of the pathway 
B)  includes only diffusion-controlled reactions 
C)  allows for substrates to be passed to alternative pathways 
D)  is a point that starts a cascade effect 
A)  is a good point for regulation of the pathway 
B)  includes only diffusion-controlled reactions 
C)  allows for substrates to be passed to alternative pathways 
D)  is a point that starts a cascade effect

Question 5

Which of the following is not a precursor for gluconeogenesis?

Accepted Answer

A)  alanine 
B)  glycerol 
C)  oxaloacetate 
D)  acetate 
E)  ethanol 
A)  alanine 
B)  glycerol 
C)  oxaloacetate 
D)  acetate 
E)  ethanol

Question 6

What is the driving force for the reaction catalyzed by UDP-glucose pyrophosphorylase that converts glucose 1-phosphate to UDP-glucose?

Accepted Answer

A)  its large negative free energy change 
B)  the formation of an energy-rich product 
C)  the subsequent hydrolysis of pyrophosphate 
D)  the change in concentration of UTP 
A)  its large negative free energy change 
B)  the formation of an energy-rich product 
C)  the subsequent hydrolysis of pyrophosphate 
D)  the change in concentration of UTP

Question 7

Gluconeogenesis uses the same enzymatic reactions of glycolysis except for the .

Accepted Answer

A)  pyruvate kinase catalyzed step 
B)  4 irreversible reactions in glycolysis 
C)  3 irreversible reactions in glycolysis 
D)  2 irreversible reactions in glycolysis 
A)  pyruvate kinase catalyzed step 
B)  4 irreversible reactions in glycolysis 
C)  3 irreversible reactions in glycolysis 
D)  2 irreversible reactions in glycolysis

Question 8

The reaction that converts amino acids into keto acids such as pyruvate) is called

Accepted Answer

A)  the Cori cycle. 
B)  catabolism. 
C)  transamination. 
D)  dehydrogenation. 
A)  the Cori cycle. 
B)  catabolism. 
C)  transamination. 
D)  dehydrogenation.

Question 9

Glycogen degradation occurs in

Accepted Answer

A)  muscle. 
B)  liver. 
C)  muscle and liver. 
D)  saliva. 
E)  brain cells. 
A)  muscle. 
B)  liver. 
C)  muscle and liver. 
D)  saliva. 
E)  brain cells.

Question 10

All blood glucose in humans is derived from carbohydrate sources included in the diet.

Accepted Answer

A) True 
 B)False

Question 11

Why does glycolysis produce more energy more ATP) from glucose units released by glycogen degradation than from free glucose?

Accepted Answer

A)  Limit dextrin contains additional molecules. 
B)  The debranching enzyme releases free glucose. 
C)  The glucose is already phosphorylated after glycogen phosphorylase action. 
D)  The glucose from glycogen degradation bypasses glycolysis. 
E)  All of the above 
A)  Limit dextrin contains additional molecules. 
B)  The debranching enzyme releases free glucose. 
C)  The glucose is already phosphorylated after glycogen phosphorylase action. 
D)  The glucose from glycogen degradation bypasses glycolysis. 
E)  All of the above

Question 12

The sequence of enzymes active in liver to degrade glycogen in response to glucagon is: . ~P indicates phosphorylation)

Accepted Answer

A)  phosphorylase kinase, glycogen phosphorylase b, protein kinase A, glucagon 
B)  glucagon, phosphorylase kinase, glycogen phosphorylase b, protein kinase A 
C)  glucagon, Protein kinase A, phosphorylase kinase~P, glycogen phosphorylase a~P 
D)  glucagon, protein kinase A, glycogen phosphorylase a~P, phosphorylase kinase~P 
A)  phosphorylase kinase, glycogen phosphorylase b, protein kinase A, glucagon 
B)  glucagon, phosphorylase kinase, glycogen phosphorylase b, protein kinase A 
C)  glucagon, Protein kinase A, phosphorylase kinase~P, glycogen phosphorylase a~P 
D)  glucagon, protein kinase A, glycogen phosphorylase a~P, phosphorylase kinase~P

Question 13

The activity of glycogen phosphorylase can be controlled by

Accepted Answer

A)  phosphorylation. 
B)  ATP. 
C)  glucose 6-phosphate. 
D)  protein subunit separation. 
E)  All of the above 
A)  phosphorylation. 
B)  ATP. 
C)  glucose 6-phosphate. 
D)  protein subunit separation. 
E)  All of the above

Question 14

The sequence of glucose oxidation to lactate in peripheral tissues, delivery of lactate to the liver, formation of glucose from lactate in the liver, and delivery of glucose back to peripheral tissues is known as the .

Accepted Answer

A)  glyoxylate cycle 
B)  Krebʹs cycle 
C)  Cori cycle 
D)  gluconeogenesis cycle 
A)  glyoxylate cycle 
B)  Krebʹs cycle 
C)  Cori cycle 
D)  gluconeogenesis cycle

Question 15

UDP-glucose is a precursor of glycogen in all cells.

Accepted Answer

A) True 
 B)False

Question 16

The reaction catalyzed by polyol dehydrogenase involves the reduction of sorbitol.

Accepted Answer

A) True 
 B)False

Question 17

Phosphorylation can be used to either inactive or activate enzymes. This is a key element in the regulation of glucose metabolism. Phosphorylation of glycogen phosphorylase it; phosphorylation of glycogen synthase it.

Accepted Answer

A)  activates; activates 
B)  activates; inactivates 
C)  inactivates; inactivates 
D)  inactivates; activates 
A)  activates; activates 
B)  activates; inactivates 
C)  inactivates; inactivates 
D)  inactivates; activates

Question 18

Ruminants, like cows, can utilize propionate as a precursor for gluconeogenesis.

Accepted Answer

A) True 
 B)False

Question 19

Glycogen storage disease results in glycogen accumulation in the liver and kidneys. It can be controlled by changing the diet.

Accepted Answer

A) True 
 B)False

Question 20

In addition to control of activity by phosphorylation, phosphorylase kinase is activated by

Accepted Answer

A)  Calmodulin. 
B)  Ca2+. 
C)  cAMP. 
D)  Inhibitor-1. 
A)  Calmodulin. 
B)  Ca2+. 
C)  cAMP. 
D)  Inhibitor-1.

Exam 12: Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

Unlike liver tissue, muscle and some other tissues differ in regulation of glycogen metabolism because

Glycogen phosphorylaseacts on the non-reducing ends of glycogen.

Which statement is true about the reaction catalyzed by glycogen synthase?

A substrate cycle in a metabolic pathway .

Which of the following is not a precursor for gluconeogenesis?

What is the driving force for the reaction catalyzed by UDP-glucose pyrophosphorylase that converts glucose 1-phosphate to UDP-glucose?

Gluconeogenesis uses the same enzymatic reactions of glycolysis except for the .

The reaction that converts amino acids into keto acids such as pyruvate) is called

Glycogen degradation occurs in

All blood glucose in humans is derived from carbohydrate sources included in the diet.

Why does glycolysis produce more energy more ATP) from glucose units released by glycogen degradation than from free glucose?

The sequence of enzymes active in liver to degrade glycogen in response to glucagon is: . ~P indicates phosphorylation)

The activity of glycogen phosphorylase can be controlled by

The sequence of glucose oxidation to lactate in peripheral tissues, delivery of lactate to the liver, formation of glucose from lactate in the liver, and delivery of glucose back to peripheral tissues is known as the .

UDP-glucose is a precursor of glycogen in all cells.

The reaction catalyzed by polyol dehydrogenase involves the reduction of sorbitol.

Phosphorylation can be used to either inactive or activate enzymes. This is a key element in the regulation of glucose metabolism. Phosphorylation of glycogen phosphorylase it; phosphorylation of glycogen synthase it.

Ruminants, like cows, can utilize propionate as a precursor for gluconeogenesis.

Glycogen storage disease results in glycogen accumulation in the liver and kidneys. It can be controlled by changing the diet.

In addition to control of activity by phosphorylation, phosphorylase kinase is activated by

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

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