Question 1

An intermediate found in gluconeogenesis and not glycolysis is

Accepted Answer

A) 2-phosphoglycerate. 
B) oxaloacetate. 
C) phosphoenolpyruvate. 
D) fructose 1,6-bisphosphate. 
A) 2-phosphoglycerate. 
B) oxaloacetate. 
C) phosphoenolpyruvate. 
D) fructose 1,6-bisphosphate.

Question 2

Possible treatment for diabetes are inhibitors of glycogen phosphorylase that mimic the natural inhibitory activity of ________ in non-diabetic persons.

Accepted Answer

A) glucagon 
B) insulin 
C) cyclic AMP 
D) glucose 
A) glucagon 
B) insulin 
C) cyclic AMP 
D) glucose

Question 3

The major regulatory step of the pentose phosphate pathway is catalyzed by which enzyme?

Accepted Answer

A) Transaldolase. 
B) Phosphofructokinase-1. 
C) Glucose 6-phosphate dehydrogenase. 
D) Ribose 5-phosphate isomerase. 
A) Transaldolase. 
B) Phosphofructokinase-1. 
C) Glucose 6-phosphate dehydrogenase. 
D) Ribose 5-phosphate isomerase.

Question 4

Which is an intermediate formed in the conversion of glucose to fructose?

Accepted Answer

A) Glucose-1-phosphate. 
B) Sorbitol. 
C) Ribose. 
D) Aldose reductase. 
A) Glucose-1-phosphate. 
B) Sorbitol. 
C) Ribose. 
D) Aldose reductase.

Question 5

Enzymes to regulate glycogen metabolism are always active when phosphorylated by protein kinases.

Accepted Answer

A) True 
 B)False

Question 6

Individuals with G6PDH deficiency have increased resistance to malaria because the parasite does not survive well in cells with

Accepted Answer

A) anemia. 
B) high levels of NADPH. 
C) low levels of NADPH. 
D) hexose 6-phosphate. 
A) anemia. 
B) high levels of NADPH. 
C) low levels of NADPH. 
D) hexose 6-phosphate.

Question 7

Glucose 1-phosphate formed by glycogen degradation is converted to glucose 6-phosphate by phosphoglucomutase.Why is this beneficial?

Accepted Answer

A) Glucose 6-phosphate is more stable. 
B) Glucose 6-phosphate is converted to free glucose. 
C) Glucose 6-phosphate is an intermediate in several pathways,including glycolysis. 
D) Glucose 6-phosphate can be transported to the liver. 
E) All of the above. 
A) Glucose 6-phosphate is more stable. 
B) Glucose 6-phosphate is converted to free glucose. 
C) Glucose 6-phosphate is an intermediate in several pathways,including glycolysis. 
D) Glucose 6-phosphate can be transported to the liver. 
E) All of the above.

Question 8

In the Cori cycle,gluconeogenesis occurs in ________ and glycolysis in ________.

Accepted Answer

A) liver;muscle 
B) liver;liver 
C) muscle;muscle 
D) muscle;liver 
A) liver;muscle 
B) liver;liver 
C) muscle;muscle 
D) muscle;liver

Question 9

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 10

Rapidly dividing cells generally have a high pentose phosphate pathway activity.

Accepted Answer

A) True 
 B)False

Question 11

The most common glycogen storage disease is called von Gierke disease caused by a deficiency in glucose 6-phosphatase.

Accepted Answer

A) True 
 B)False

Question 12

Phosphorylation can be used to either inactivate 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 13

The enzyme for the key regulatory step in glycogen biosynthesis is

Accepted Answer

A) glycogen synthase. 
B) glycogenin. 
C) branching enzyme. 
D) phosphoglucomutase. 
E) UDP-glucose pyrophosphorylase. 
A) glycogen synthase. 
B) glycogenin. 
C) branching enzyme. 
D) phosphoglucomutase. 
E) UDP-glucose pyrophosphorylase.

Question 14

Fructose 2,6-bisphosphate is a modulator that can stimulate either glycolysis or gluconeogenesis,depending on cellular glucose concentrations.

Accepted Answer

A) True 
 B)False

Question 15

Glucose monomers can be released to fuel energy by degradation of

Accepted Answer

A) stored glycogen. 
B) starch. 
C) dextrin. 
D) A and B. 
E) A,B and C. 
A) stored glycogen. 
B) starch. 
C) dextrin. 
D) A and B. 
E) A,B and C.

Question 16

Under starvation conditions,about how long does it take in humans for the body to deplete the glycogen store in the liver?

Accepted Answer

A) 10 minutes 
B) 4 hours 
C) 24 hours 
D) 1 week 
A) 10 minutes 
B) 4 hours 
C) 24 hours 
D) 1 week

Question 17

Which statement is false about glucagon?

Accepted Answer

A) It forms a protein scaffold for glycogen. 
B) It is a hormone that contains 29 amino acids. 
C) Elevated levels are associated with a fasting state. 
D) It is produced in the pancreas. 
A) It forms a protein scaffold for glycogen. 
B) It is a hormone that contains 29 amino acids. 
C) Elevated levels are associated with a fasting state. 
D) It is produced in the pancreas.

Question 18

Any compound that can be converted to ________ can be a precursor for gluconeogenesis.

Accepted Answer

A) citrate 
B) pyruvate 
C) oxaloacetate 
D) All of the above 
E) B or C 
A) citrate 
B) pyruvate 
C) oxaloacetate 
D) All of the above 
E) B or C

Question 19

Sorbitol does not accumulate when glucose is not elevated because

Accepted Answer

A) there is not enough NADPH to form it. 
B) aldose reductase has a high Km for glucose. 
C) aldose reductase has a low Km for glucose. 
D) fructose inhibits aldose reductase. 
A) there is not enough NADPH to form it. 
B) aldose reductase has a high Km for glucose. 
C) aldose reductase has a low Km for glucose. 
D) fructose inhibits aldose reductase.

Question 20

Glucagon increases the transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK)in gluconeogenesis,while insulin decreases it.

Accepted Answer

A) True 
 B)False

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

An intermediate found in gluconeogenesis and not glycolysis is

Possible treatment for diabetes are inhibitors of glycogen phosphorylase that mimic the natural inhibitory activity of ________ in non-diabetic persons.

The major regulatory step of the pentose phosphate pathway is catalyzed by which enzyme?

Which is an intermediate formed in the conversion of glucose to fructose?

Enzymes to regulate glycogen metabolism are always active when phosphorylated by protein kinases.

Individuals with G6PDH deficiency have increased resistance to malaria because the parasite does not survive well in cells with

Glucose 1-phosphate formed by glycogen degradation is converted to glucose 6-phosphate by phosphoglucomutase.Why is this beneficial?

In the Cori cycle,gluconeogenesis occurs in ________ and glycolysis in ________.

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

Rapidly dividing cells generally have a high pentose phosphate pathway activity.

The most common glycogen storage disease is called von Gierke disease caused by a deficiency in glucose 6-phosphatase.

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

The enzyme for the key regulatory step in glycogen biosynthesis is

Fructose 2,6-bisphosphate is a modulator that can stimulate either glycolysis or gluconeogenesis,depending on cellular glucose concentrations.

Glucose monomers can be released to fuel energy by degradation of

Under starvation conditions,about how long does it take in humans for the body to deplete the glycogen store in the liver?

Which statement is false about glucagon?

Any compound that can be converted to ________ can be a precursor for gluconeogenesis.

Sorbitol does not accumulate when glucose is not elevated because

Glucagon increases the transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK)in gluconeogenesis,while insulin decreases it.

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 Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

In the Cori cycle,gluconeogenesis occurs in and glycolysis in .

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