Question 1

Gluconeogenesis is favored when citrate levels are , when AMP levels are __________, and when ATP levels are _.

Accepted Answer

A)  low; low; high 
B)  high; low; high 
C)  low; high; low 
D)  high; high; low 
A)  low; low; high 
B)  high; low; high 
C)  low; high; low 
D)  high; high; low

Question 2

In the gluconeogenesis pathway, the enzyme glucose-6-phosphatase reverses which step in glycolysis?

Accepted Answer

A)  the formation of glucose 
B)  the reaction catalyzed by pyruvate dehydrogenase 
C)  the reaction catalyzed by hexokinase 
D)  the formation of fructose-1,6-bisphosphate 
A)  the formation of glucose 
B)  the reaction catalyzed by pyruvate dehydrogenase 
C)  the reaction catalyzed by hexokinase 
D)  the formation of fructose-1,6-bisphosphate

Question 3

What enzyme class in the nonoxidative phase of the pentose phosphate pathway allows for the reaction of ribose-5-phosphate and xylulose-5-phosphate to produce glyceraldehyde-3-phosphate and seduheptulose-7-phosphate?

Accepted Answer

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

Question 4

Which enzyme in the pentose phosphate pathway catalyzes the following reaction?

Accepted Answer

A)  glucose-6-phosphate dehydrogenase 
B)  transaldolase 
C)  6-phosphogluconate dehydrogenase 
D)  ribulose-5-phosphate epimerase 
A)  glucose-6-phosphate dehydrogenase 
B)  transaldolase 
C)  6-phosphogluconate dehydrogenase 
D)  ribulose-5-phosphate epimerase

Question 5

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 6

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 7

Which enzyme in the glycolysis pathway catalyzes a reaction that requires two enzymes to reverse in the gluconeogenesis pathway?

Accepted Answer

A)  pyruvate kinase 
B)  phosphofructokinase I 
C)  pyruvate dehydrogenase 
D)  glycogen phosphorylase 
A)  pyruvate kinase 
B)  phosphofructokinase I 
C)  pyruvate dehydrogenase 
D)  glycogen phosphorylase

Question 8

The gluconeogenesis reaction shown below is missing some reactants and products. What class of enzyme catalyzes this reaction?

Accepted Answer

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

Question 9

Name the four enzymes of the gluconeogenesis pathway that are NOT found in the glycolysis pathway.

Accepted Answer

Pyruvate carboxylase, phosphoe

Question 10

During vigorous exercise the lactate produced in the muscle travels to the liver for recycling. Explain why starting with lactate is beneficial for the liver gluconeogenesis pathway.

Accepted Answer

Lactate in the liver (1) can be converte

Question 11

Which enzyme in the pentose phosphate pathway is regulated to control flux through the pathway?

Accepted Answer

A)  glucose-6-phosphate dehydrogenase 
B)  transaldolase 
C)  6-phosphogluconate dehydrogenase 
D)  ribulose-5-phosphate epimerase 
A)  glucose-6-phosphate dehydrogenase 
B)  transaldolase 
C)  6-phosphogluconate dehydrogenase 
D)  ribulose-5-phosphate epimerase

Question 12

Name each of the distinct catalytic activities of the debranching enzyme.

Accepted Answer

The debranching enzyme approaches a bran

Question 13

Which enzyme class catalyzes the following pentose phosphate pathway reaction?

Accepted Answer

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

Question 14

The Cori cycle

Accepted Answer

A)  requires both glycolysis and gluconeogenesis pathways. 
B)  removes lactic acid from liver cells and delivers it to muscle cells. 
C)  involves the regeneration of NADH equivalents for the working muscles. 
D)  converts glucose into lactic acid. 
A)  requires both glycolysis and gluconeogenesis pathways. 
B)  removes lactic acid from liver cells and delivers it to muscle cells. 
C)  involves the regeneration of NADH equivalents for the working muscles. 
D)  converts glucose into lactic acid.

Question 15

Gluconeogenesis would most likely be allosterically activated simultaneously along with which other metabolic process?

Accepted Answer

A)  glycolysis 
B)  pentose phosphate pathway 
C)  glycogen synthesis 
D)  TCA cycle 
A)  glycolysis 
B)  pentose phosphate pathway 
C)  glycogen synthesis 
D)  TCA cycle

Question 16

Name the enzymes in the glycolysis or gluconeogenesis pathway that could be inhibited by ATP.

Accepted Answer

In glycolysis, enzymes that ar

Question 17

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 18

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

Accepted Answer

Dehydrogen

Question 19

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 20

The conversion of pyruvate to phosphoenolpyruvate (PEP) in gluconeogenesis

Accepted Answer

A)  requires the net input of two equivalents of NADH. 
B)  occurs in two steps and is catalyzed by the enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase. 
C)  is a thermodynamically spontaneous reaction that gives rise to a stable product. 
D)  requires lactate as a precursor. 
A)  requires the net input of two equivalents of NADH. 
B)  occurs in two steps and is catalyzed by the enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase. 
C)  is a thermodynamically spontaneous reaction that gives rise to a stable product. 
D)  requires lactate as a precursor.

Exam 14: Carbohydrate Metabolism

Gluconeogenesis is favored when citrate levels are , when AMP levels are __________, and when ATP levels are _.

In the gluconeogenesis pathway, the enzyme glucose-6-phosphatase reverses which step in glycolysis?

What enzyme class in the nonoxidative phase of the pentose phosphate pathway allows for the reaction of ribose-5-phosphate and xylulose-5-phosphate to produce glyceraldehyde-3-phosphate and seduheptulose-7-phosphate?

Which enzyme in the pentose phosphate pathway catalyzes the following reaction?

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

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

Which enzyme in the glycolysis pathway catalyzes a reaction that requires two enzymes to reverse in the gluconeogenesis pathway?

The gluconeogenesis reaction shown below is missing some reactants and products. What class of enzyme catalyzes this reaction?

Name the four enzymes of the gluconeogenesis pathway that are NOT found in the glycolysis pathway.

During vigorous exercise the lactate produced in the muscle travels to the liver for recycling. Explain why starting with lactate is beneficial for the liver gluconeogenesis pathway.

Which enzyme in the pentose phosphate pathway is regulated to control flux through the pathway?

Name each of the distinct catalytic activities of the debranching enzyme.

Which enzyme class catalyzes the following pentose phosphate pathway reaction?

The Cori cycle

Gluconeogenesis would most likely be allosterically activated simultaneously along with which other metabolic process?

Name the enzymes in the glycolysis or gluconeogenesis pathway that could be inhibited by ATP.

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

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

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

The conversion of pyruvate to phosphoenolpyruvate (PEP) in gluconeogenesis

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

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