Question 1

Under aerobic conditions yeast cells convert pyruvate to ethanol and carbon dioxide.

Accepted Answer

A) True 
 B)False

Question 2

Triose phosphate isomerase is diffusion controlled.

Accepted Answer

A) True 
 B)False

Question 3

Arsenite

Accepted Answer

A) poisons by the same mechanism as arsenate. 
B) is less toxic than arsenate. 
C) binds tightly to lipoamide sulfur atoms. 
D) None of the above. 
A) poisons by the same mechanism as arsenate. 
B) is less toxic than arsenate. 
C) binds tightly to lipoamide sulfur atoms. 
D) None of the above.

Question 4

The glucose 6-phospate isomerase reaction is a near-equilibrium reaction.Therefore,at any time in a cell there is

Accepted Answer

A) little or no glucose- 6-phospate remaining. 
B) about equal amounts of glucose- 6-phosphate and fructose -6-phospate. 
C) an accumulation of fructose 6-phosphate. 
D) All of the above. 
A) little or no glucose- 6-phospate remaining. 
B) about equal amounts of glucose- 6-phosphate and fructose -6-phospate. 
C) an accumulation of fructose 6-phosphate. 
D) All of the above.

Question 5

Enzymes that catalyze the same reaction are called ________.

Accepted Answer

A) isozymes 
B) complementary enzymes 
C) cofactors 
D) catalytes 
A) isozymes 
B) complementary enzymes 
C) cofactors 
D) catalytes

Question 6

Which of the following elements is required for the enzymatic reaction that produces phosphoenolpyruvate?

Accepted Answer

A) Potassium. 
B) Calcium. 
C) Magnesium. 
D) Manganese. 
A) Potassium. 
B) Calcium. 
C) Magnesium. 
D) Manganese.

Question 7

Substrate level phosphorylation

Accepted Answer

A) describes the conversion of ADP into ATP with the addition of inorganic phosphate every place throughout the cell. 
B) describes the formation of ADP by phosphoryl group transfer from 1,3 bisphosphoglycerate. 
C) is the formation of ATP by phosphoryl group transfer from a higher energy compound. 
D) Both A and C. 
A) describes the conversion of ADP into ATP with the addition of inorganic phosphate every place throughout the cell. 
B) describes the formation of ADP by phosphoryl group transfer from 1,3 bisphosphoglycerate. 
C) is the formation of ATP by phosphoryl group transfer from a higher energy compound. 
D) Both A and C.

Question 8

Which substance causes muscles to ache during strenuous exercise?

Accepted Answer

A) Pyruvic acid. 
B) Lactose dehydrogenase. 
C) Lactate ion. 
D) Lactic acid. 
A) Pyruvic acid. 
B) Lactose dehydrogenase. 
C) Lactate ion. 
D) Lactic acid.

Question 9

Which statement is false about the Entner-Doudoroff pathway?

Accepted Answer

A) It produces less ATP per glucose molecule than glycolysis. 
B) Organisms that have this pathway use it only under conditions of low glyceraldehyde 3-phosphate isomerase concentrations. 
C) It is useful for bacteria that do not have PFK-1. 
D) The pathway produces pyruvate and glyceraldehyde 3-phosphate. 
E) It enables some bacteria to survive on gluconate and other organic acids that cannot be metabolized via glycolysis. 
A) It produces less ATP per glucose molecule than glycolysis. 
B) Organisms that have this pathway use it only under conditions of low glyceraldehyde 3-phosphate isomerase concentrations. 
C) It is useful for bacteria that do not have PFK-1. 
D) The pathway produces pyruvate and glyceraldehyde 3-phosphate. 
E) It enables some bacteria to survive on gluconate and other organic acids that cannot be metabolized via glycolysis.

Question 10

Transfer of the phosphoryl group from PEP to ADP is an example of

Accepted Answer

A) a mutase reaction. 
B) isomerization. 
C) dehydrogenase. 
D) substrate-level phosphorylation. 
A) a mutase reaction. 
B) isomerization. 
C) dehydrogenase. 
D) substrate-level phosphorylation.

Question 11

A cell that has been fed glucose containing carbon - radioactive with carbon 14 in carbon #1 will have ________ percent of the radioactivity in each mole of glyceraldehyde-3-phosphate.

Accepted Answer

A) 0% 
B) 25% 
C) 50% 
D) 100% 
A) 0% 
B) 25% 
C) 50% 
D) 100%

Question 12

Citrate is an intermediate in the citric acid cycle,yet it is also an inhibitor of PFK-1.Elevated citrate indicates that the citric acid cycle is blocked so further production of pyruvate is no longer necessary.This is an example of feedback inhibition.

Accepted Answer

A) True 
 B)False

Question 13

What chemical species activates the GLUT4 protein to transport glucose into cells?

Accepted Answer

A) Adrenaline. 
B) Insulin. 
C) Protein kinase A. 
D) PFK-2. 
A) Adrenaline. 
B) Insulin. 
C) Protein kinase A. 
D) PFK-2.

Question 14

The molecule 1,3-bisphosphoglycerate can be converted to 3-phosphoenolpyruvate two ways.One way is catalyzed by the glycolytic pathway enzyme phosphoglycerate kinase.The other route is a two step reaction sequence that uses the enzymes bisphosphoglycerate mutase and 2,3-bisphosphoglycerate phosphatase.The intermediate product of the two-step sequence is 2,3-BPG which is an allosteric inhibitor of hemoglobin.What disadvantage would there be if the glycolytic pathway only used the two-step reaction sequence?

Accepted Answer

A) The step catalyzed by phosphoglycerate kinase is one of the ATP producing steps of glycolysis.Using only the two-step reaction sequence would reduce the number of ATP's produced. 
B) There is no disadvantage to the two-step sequence other than having to use more than one enzyme. 
C) The molecule 2,3-BPG is also a potent inhibitor of PFK-1.Even transient production of 2,3-BPG will significantly slow glycolysis. 
D) Too much 2,3-BPG would be produced which would cause clumping of red blood cells. 
A) The step catalyzed by phosphoglycerate kinase is one of the ATP producing steps of glycolysis.Using only the two-step reaction sequence would reduce the number of ATP's produced. 
B) There is no disadvantage to the two-step sequence other than having to use more than one enzyme. 
C) The molecule 2,3-BPG is also a potent inhibitor of PFK-1.Even transient production of 2,3-BPG will significantly slow glycolysis. 
D) Too much 2,3-BPG would be produced which would cause clumping of red blood cells.

Question 15

How does mannose enter the glycolytic pathway?

Accepted Answer

A) It is converted mannose 6-phosphate and then isomerized to fructose 6-phosphate which enters the pathway. 
B) It can enter directly into the first step of glycolysis because hexokinase converts mannose to glucose 6-phosphate. 
C) Mannose is first split into two trioses that are directly converted to glyceraldehyde 3-phosphate. 
D) Mannose is not metabolized via glycolysis.It enters a separate pathway. 
A) It is converted mannose 6-phosphate and then isomerized to fructose 6-phosphate which enters the pathway. 
B) It can enter directly into the first step of glycolysis because hexokinase converts mannose to glucose 6-phosphate. 
C) Mannose is first split into two trioses that are directly converted to glyceraldehyde 3-phosphate. 
D) Mannose is not metabolized via glycolysis.It enters a separate pathway.

Question 16

Once inside a cell,glucose is rapidly phosphorylated to glucose-6-phosphate.What is the main purpose of this phosphorylation?

Accepted Answer

A) To keep glucose inside the cell. 
B) To form a high-energy compound. 
C) To activate PFK-1. 
D) To prevent mutarotation. 
A) To keep glucose inside the cell. 
B) To form a high-energy compound. 
C) To activate PFK-1. 
D) To prevent mutarotation.

Question 17

After strenuous exercise the acidosis due to release of protons during ATP hydrolysis is the likely source of most of the pain,not lactate accumulation.

Accepted Answer

A) True 
 B)False

Question 18

Transfer of a high-energy phosphoryl group to ADP,resulting in ATP occurs when

Accepted Answer

A) 1,3-bisphosphoglycerate → 3-phosphoglycerate. 
B) phosphoenolpyruvate (PEP)→ pyruvate. 
C) 3-phosphoglycerate → 2-phosphoglycerate. 
D) Both A and B. 
E) None of the above. 
A) 1,3-bisphosphoglycerate → 3-phosphoglycerate. 
B) phosphoenolpyruvate (PEP)→ pyruvate. 
C) 3-phosphoglycerate → 2-phosphoglycerate. 
D) Both A and B. 
E) None of the above.

Question 19

Which is among the possible fates of pyruvate after glycolysis?

Accepted Answer

A) Conversion to lactate. 
B) Further reduction by the citric acid cycle. 
C) Conversion to ethanol. 
D) All of the above. 
A) Conversion to lactate. 
B) Further reduction by the citric acid cycle. 
C) Conversion to ethanol. 
D) All of the above.

Question 20

During glycolysis,isomerization occurs during which of the following reactions?

Accepted Answer

A) Fructose 1,6-bisphosphate → dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. 
B) Fructose 6-phosphate → fructose 1,6-bisphosphate. 
C) Glucose 6- phosphate → fructose 6- phosphate. 
D) Glucose → glucose 6- phosphate. 
A) Fructose 1,6-bisphosphate → dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. 
B) Fructose 6-phosphate → fructose 1,6-bisphosphate. 
C) Glucose 6- phosphate → fructose 6- phosphate. 
D) Glucose → glucose 6- phosphate.

Exam 11: Glycolysis

Under aerobic conditions yeast cells convert pyruvate to ethanol and carbon dioxide.

Triose phosphate isomerase is diffusion controlled.

Arsenite

The glucose 6-phospate isomerase reaction is a near-equilibrium reaction.Therefore,at any time in a cell there is

Enzymes that catalyze the same reaction are called ________.

Which of the following elements is required for the enzymatic reaction that produces phosphoenolpyruvate?

Substrate level phosphorylation

Which substance causes muscles to ache during strenuous exercise?

Which statement is false about the Entner-Doudoroff pathway?

Transfer of the phosphoryl group from PEP to ADP is an example of

A cell that has been fed glucose containing carbon - radioactive with carbon 14 in carbon #1 will have ________ percent of the radioactivity in each mole of glyceraldehyde-3-phosphate.

Citrate is an intermediate in the citric acid cycle,yet it is also an inhibitor of PFK-1.Elevated citrate indicates that the citric acid cycle is blocked so further production of pyruvate is no longer necessary.This is an example of feedback inhibition.

What chemical species activates the GLUT4 protein to transport glucose into cells?

How does mannose enter the glycolytic pathway?

Once inside a cell,glucose is rapidly phosphorylated to glucose-6-phosphate.What is the main purpose of this phosphorylation?

After strenuous exercise the acidosis due to release of protons during ATP hydrolysis is the likely source of most of the pain,not lactate accumulation.

Transfer of a high-energy phosphoryl group to ADP,resulting in ATP occurs when

Which is among the possible fates of pyruvate after glycolysis?

During glycolysis,isomerization occurs during which of the following reactions?

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

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

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

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