Question 1

Which correctly describes the role of the transport system shown below?

Accepted Answer

A)  It provides an alternate fate for pyruvate degradation. 
B)  It provides a source of NADH for gluconeogenesis via malate transport. 
C)  It converts NADH equivalents into reduced forms of carbon. 
D)  It allows for pyruvate transport into and out of the mitochondria. 
A)  It provides an alternate fate for pyruvate degradation. 
B)  It provides a source of NADH for gluconeogenesis via malate transport. 
C)  It converts NADH equivalents into reduced forms of carbon. 
D)  It allows for pyruvate transport into and out of the mitochondria.

Question 2

What is the name of the enzyme that removes phosphate groups from the regulated glycogen metabolism enzymes to reverse their activity?

Accepted Answer

A)  phosphorylase kinase 
B)  protein phosphatase 1 
C)  insulin 
D)  protein kinase A 
A)  phosphorylase kinase 
B)  protein phosphatase 1 
C)  insulin 
D)  protein kinase A

Question 3

What molecule activates the pentose phosphate pathway?

Accepted Answer

A)  NADP+ 
B)  ribulose-5-phosphate 
C)  ADP 
D)  NADH 
A)  NADP+ 
B)  ribulose-5-phosphate 
C)  ADP 
D)  NADH

Question 4

The hormone insulin stimulates __________ and inhibits __________,leading to a(n)__________ in the glucose levels.

Accepted Answer

A)  glycogen synthase; glycogen phosphorylase; decrease 
B)  glycogen phosphorylase; glycogen synthase; decrease 
C)  glycogen synthase; glycogen phosphorylase; increase 
D)  glycogen phosphorylase; glycogen synthase; increase 
A)  glycogen synthase; glycogen phosphorylase; decrease 
B)  glycogen phosphorylase; glycogen synthase; decrease 
C)  glycogen synthase; glycogen phosphorylase; increase 
D)  glycogen phosphorylase; glycogen synthase; increase

Question 5

Which one of the following is involved in the breakdown of glycogen?

Accepted Answer

A)  inorganic phosphate 
B)  ATP 
C)  branching enzyme 
D)  hexokinase 
A)  inorganic phosphate 
B)  ATP 
C)  branching enzyme 
D)  hexokinase

Question 6

How many of the 10 glycolysis reactions use the same enzyme in the gluconeogenesis pathway?

Accepted Answer

A)  10 
B)  7 
C)  5 
D)  3 
A)  10 
B)  7 
C)  5 
D)  3

Question 7

List the three enzymes in glycolysis that are bypassed in gluconeogenesis and match them with the enzymes in gluconeogenesis that replace them.

Accepted Answer

(1)Hexokinase is replaced by glucose-1-p

Question 8

Which enzyme class catalyzes the following pentose phosphate pathway reaction (note that there may be some missing reactants and products)?

Accepted Answer

A)  lyase 
B)  isomerase 
C)  transferase 
D)  oxidoreductase 
A)  lyase 
B)  isomerase 
C)  transferase 
D)  oxidoreductase

Question 9

Draw a glucose molecule and indicate which atom is linked to glycogen during the glycogen synthesis process.

Accepted Answer

The C1 of the incomi

Question 10

The opposing glycolysis and gluconeogenesis enzymes hexokinase and glucose-6-phosphatase are located with which cellular locations,respectively?

Accepted Answer

Hexokinase is found in the cyt

Question 11

Which of the following molecules might inhibit the regulated enzymes in glycolysis?

Accepted Answer

A)  NAD+ 
B)  ATP 
C)  AMP 
D)  fructose-2,6-bisphosphate 
A)  NAD+ 
B)  ATP 
C)  AMP 
D)  fructose-2,6-bisphosphate

Question 12

What class of enzymes in the oxidative phase of the pentose phosphate pathway is responsible for the production of NADPH?

Accepted Answer

Dehydrogen

Question 13

What triggers the Cori cycle?

Accepted Answer

A)  a buildup of cellular NAD+ 
B)  oxygen-limited working muscle cells 
C)  low levels of glucose in the muscle cells 
D)  elevated glucagon levels 
A)  a buildup of cellular NAD+ 
B)  oxygen-limited working muscle cells 
C)  low levels of glucose in the muscle cells 
D)  elevated glucagon levels

Question 14

The pentose phosphate pathway

Accepted Answer

A)  resembles the TCA cycle in that it couples the loss of CO2 with the formation of NADH. 
B)  allows 5C sugars to converge with or diverge from the glycolysis pathway. 
C)  contains 2C, 3C, 4C, 5C, 6C, and 7C sugar molecules. 
D)  enables the production of ATP from glucose. 
A)  resembles the TCA cycle in that it couples the loss of CO2 with the formation of NADH. 
B)  allows 5C sugars to converge with or diverge from the glycolysis pathway. 
C)  contains 2C, 3C, 4C, 5C, 6C, and 7C sugar molecules. 
D)  enables the production of ATP from glucose.

Question 15

What are the three main sources of carbon in animals making glucose with the gluconeogenesis pathway?

Accepted Answer

(1)Glycerol from fats,(2)lacta

Question 16

The main function of the pentose phosphate pathway is to provide

Accepted Answer

A)  the cell with backup capability when glycolysis is inhibited. 
B)  energy and reducing power. 
C)  a mechanism for the utilization of the carbon skeletons of excess amino acids. 
D)  a source of ribose and NADPH. 
A)  the cell with backup capability when glycolysis is inhibited. 
B)  energy and reducing power. 
C)  a mechanism for the utilization of the carbon skeletons of excess amino acids. 
D)  a source of ribose and NADPH.

Question 17

The branching enzyme

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 18

If the ratio of NADP+ to NADPH were high,the

Accepted Answer

A)  net production of ATP would occur. 
B)  pentose phosphate pathway oxidative phase would be activated. 
C)  cellular levels of nucleotides would have to increase from an activated pentose phosphate pathway. 
D)  pentose phosphate pathway would be inhibited. 
A)  net production of ATP would occur. 
B)  pentose phosphate pathway oxidative phase would be activated. 
C)  cellular levels of nucleotides would have to increase from an activated pentose phosphate pathway. 
D)  pentose phosphate pathway would be inhibited.

Question 19

Which of the following molecules would activate phosphofructokinase 1 (PFK1)?

Accepted Answer

A)  NADH 
B)  AMP 
C)  ATP 
D)  pyruvate 
A)  NADH 
B)  AMP 
C)  ATP 
D)  pyruvate

Question 20

Cori disease arises from a deficient debranching enzyme.Describe the consequences for glycogen metabolism.

Accepted Answer

Individuals with Cori disease

Exam 14: Carbohydrate Metabolism

Which correctly describes the role of the transport system shown below?

What is the name of the enzyme that removes phosphate groups from the regulated glycogen metabolism enzymes to reverse their activity?

What molecule activates the pentose phosphate pathway?

The hormone insulin stimulates __________ and inhibits __________,leading to a(n)__________ in the glucose levels.

Which one of the following is involved in the breakdown of glycogen?

How many of the 10 glycolysis reactions use the same enzyme in the gluconeogenesis pathway?

List the three enzymes in glycolysis that are bypassed in gluconeogenesis and match them with the enzymes in gluconeogenesis that replace them.

Which enzyme class catalyzes the following pentose phosphate pathway reaction (note that there may be some missing reactants and products)?

Draw a glucose molecule and indicate which atom is linked to glycogen during the glycogen synthesis process.

The opposing glycolysis and gluconeogenesis enzymes hexokinase and glucose-6-phosphatase are located with which cellular locations,respectively?

Which of the following molecules might inhibit the regulated enzymes in glycolysis?

What class of enzymes in the oxidative phase of the pentose phosphate pathway is responsible for the production of NADPH?

What triggers the Cori cycle?

The pentose phosphate pathway

What are the three main sources of carbon in animals making glucose with the gluconeogenesis pathway?

The main function of the pentose phosphate pathway is to provide

The branching enzyme

If the ratio of NADP+ to NADPH were high,the

Which of the following molecules would activate phosphofructokinase 1 (PFK1)?

Cori disease arises from a deficient debranching enzyme.Describe the consequences for glycogen metabolism.

Principles of Biochemistry

Physical Biochemistry: Energy Conversion,water,and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

Dna Replication, repair, and Recombination

Rna Synthesis, processing, and Gene Silencing

Protein Synthesis, posttranslational Modification, and Transport

Gene Regulation

Filters

The hormone insulin stimulates and inhibits ,leading to a(n)__ in the glucose levels.

If the ratio of NADP⁺ to NADPH were high,the