Question 1

How many molecules of FADH2 are produced by the complete oxidation of one acetyl group by the citric acid cycle?

Accepted Answer

A) 1 
B) 2 
C) 4 
D) 6 
E) 12 
A) 1 
B) 2 
C) 4 
D) 6 
E) 12

Question 2

What molecule acts as a positive allosteric effector of the conversion of isocitrate to α-ketoglutarate in the citric acid cycle?

Accepted Answer

A) NADH 
B) ATP 
C) ADP 
D) CO2 
E) O2 
A) NADH 
B) ATP 
C) ADP 
D) CO2 
E) O2

Question 3

Which of the following structures, groups, or units does not form a part of acetyl CoA?

Accepted Answer

A) acetyl group 
B) protein unit 
C) β-mercaptoethylamine group 
D) pantothenate unit 
E) phosphorylated ADP 
A) acetyl group 
B) protein unit 
C) β-mercaptoethylamine group 
D) pantothenate unit 
E) phosphorylated ADP

Question 4

What is the role of F0 in the F0F1 complex used in oxidative phosphorylation?

Accepted Answer

A) It accepts two electrons and a hydrogen ion from NADH in forming NAD+. 
B) It accepts two electrons and two hydrogen ions from FADH2 in forming FAD. 
C) It pumps H+ out of the mitochondrial matrix into the intermembrane space. 
D) It provides the channel for the return of H+ to the matrix of the mitochondria. 
E) It uses the energy released from the flow of H+ to the matrix to synthesize ATP. 
A) It accepts two electrons and a hydrogen ion from NADH in forming NAD+. 
B) It accepts two electrons and two hydrogen ions from FADH2 in forming FAD. 
C) It pumps H+ out of the mitochondrial matrix into the intermembrane space. 
D) It provides the channel for the return of H+ to the matrix of the mitochondria. 
E) It uses the energy released from the flow of H+ to the matrix to synthesize ATP.

Question 5

What cyclic metabolic pathway is the final stage of the degradation of carbohydrates, fats, and amino acids released from dietary proteins?

Accepted Answer

A) urea cycle 
B) pentose phosphate pathway 
C) Cori cycle 
D) β-oxidation spiral 
E) citric acid cycle 
A) urea cycle 
B) pentose phosphate pathway 
C) Cori cycle 
D) β-oxidation spiral 
E) citric acid cycle

Question 6

When amino acids undergo degradation in the liver, what is the first step of the process?

Accepted Answer

A) decarboxylation 
B) removal of the α-amino group 
C) removal of the side chain R group 
D) attachment to coenzyme A 
E) C-C bond cleavage 
A) decarboxylation 
B) removal of the α-amino group 
C) removal of the side chain R group 
D) attachment to coenzyme A 
E) C-C bond cleavage

Question 7

When a molecule of glucose undergoes complete oxidation in the body, what percentage of its potential energy is harvested in the form of ATP molecules?

Accepted Answer

A) 20% 
B) 40% 
C) 60% 
D) 80% 
E) 90% 
A) 20% 
B) 40% 
C) 60% 
D) 80% 
E) 90%

Question 8

The first step of the urea cycle involves which of the following substances?

Accepted Answer

A) urea 
B) citrulline 
C) NAD+ 
D) NH4+ 
E) Pi 
A) urea 
B) citrulline 
C) NAD+ 
D) NH4+ 
E) Pi

Question 9

The conversion of isocitrate to α-ketoglutarate in step 3 of the citric acid cycle actually occurs by the two-step process shown below.What is true about step 3a?

Accepted Answer

A) The reaction is a decarboxylation reaction. 
B) The reaction is an oxidation reaction. 
C) The reaction is a dehydration reaction. 
D) The reaction is an alkene addition reaction. 
E) The reaction is a hydrolysis reaction. 
A) The reaction is a decarboxylation reaction. 
B) The reaction is an oxidation reaction. 
C) The reaction is a dehydration reaction. 
D) The reaction is an alkene addition reaction. 
E) The reaction is a hydrolysis reaction.

Question 10

Which of the following best describes the function of NAD+ and FAD in catabolic pathways?

Accepted Answer

A) competitive inhibitors of the enzymes present in each pathway 
B) oxidizing agents that accept electrons and hydrogen ions from compounds undergoing oxidation 
C) non-competitive inhibitors of the enzymes present in each pathway 
D) transport molecules that carry two-carbon acetyl units to or from the different pathways 
E) enzymes that catalyze the hydrolysis of ATP 
A) competitive inhibitors of the enzymes present in each pathway 
B) oxidizing agents that accept electrons and hydrogen ions from compounds undergoing oxidation 
C) non-competitive inhibitors of the enzymes present in each pathway 
D) transport molecules that carry two-carbon acetyl units to or from the different pathways 
E) enzymes that catalyze the hydrolysis of ATP

Question 11

Which organelle in the cytoplasm of the cell is the energy-producing factory of the cell?

Accepted Answer

A) nucleus 
B) ribosomes 
C) mitochondria 
D) lysosomes 
E) endoplasmic reticulum 
A) nucleus 
B) ribosomes 
C) mitochondria 
D) lysosomes 
E) endoplasmic reticulum

Question 12

Which correctly represents the products that result from the complete oxidation of an acetyl group in the citric acid cycle?

Accepted Answer

A) 36 ATP 
B) 2 CO2 
C) 2 CO2, 1 NADH, and 1 FADH2 
D) 2 CO2, 3 NADH, 1 FADH2, and 1 ATP 
E) 2 acetyl CoA, 1 NAD+, and 1 FAD 
A) 36 ATP 
B) 2 CO2 
C) 2 CO2, 1 NADH, and 1 FADH2 
D) 2 CO2, 3 NADH, 1 FADH2, and 1 ATP 
E) 2 acetyl CoA, 1 NAD+, and 1 FAD

Question 13

What is the name of the first compound formed in the citric acid cycle, produced by the transfer of an acetyl group from acetyl CoA to oxaloacetate?

Accepted Answer

A) acetone 
B) citrate 
C) fumarate 
D) malate 
E) carbon dioxide 
A) acetone 
B) citrate 
C) fumarate 
D) malate 
E) carbon dioxide

Question 14

The Krebs cycle begins with an aldol condensation.

Accepted Answer

A) True 
 B)False

Question 15

ATP synthase is a very large multi-lipid complex.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following compounds is a positive effector of the allosteric enzyme isocitrate dehydrogenase?

Accepted Answer

A) ATP 
B) FAD 
C) GTP 
D) ADP 
E) NADH 
A) ATP 
B) FAD 
C) GTP 
D) ADP 
E) NADH

Question 17

Which of the following substances serves as an intermediate through which all cellular energy sources are interconvertible?

Accepted Answer

A) acetyl CoA 
B) glucose 
C) ATP 
D) pyruvate 
E) citrate 
A) acetyl CoA 
B) glucose 
C) ATP 
D) pyruvate 
E) citrate

Question 18

What word is used to describe a pathway that functions in both degradative and biosynthetic reactions?

Accepted Answer

A) catabolic 
B) anabolic 
C) metabolic 
D) amphibolic 
E) diabolic 
A) catabolic 
B) anabolic 
C) metabolic 
D) amphibolic 
E) diabolic

Question 19

Which of the following compounds in high concentration inhibits the pyruvate dehydrogenase complex, the enzyme responsible for the reaction shown below?

Accepted Answer

A) acetyl CoA 
B) pyruvate 
C) ADP 
D) NAD+ 
E) FAD 
A) acetyl CoA 
B) pyruvate 
C) ADP 
D) NAD+ 
E) FAD

Question 20

How many molecules of ATP are produced by oxidative phosphorylation for each molecule of NADH produced in the citric acid cycle?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 6 
E) 18 
A) 1 
B) 2 
C) 3 
D) 6 
E) 18

Exam 22: Aerobic Respiration and Energy Production

How many molecules of FADH2 are produced by the complete oxidation of one acetyl group by the citric acid cycle?

What molecule acts as a positive allosteric effector of the conversion of isocitrate to α-ketoglutarate in the citric acid cycle?

Which of the following structures, groups, or units does not form a part of acetyl CoA?

What is the role of F0 in the F0F1 complex used in oxidative phosphorylation?

What cyclic metabolic pathway is the final stage of the degradation of carbohydrates, fats, and amino acids released from dietary proteins?

When amino acids undergo degradation in the liver, what is the first step of the process?

When a molecule of glucose undergoes complete oxidation in the body, what percentage of its potential energy is harvested in the form of ATP molecules?

The first step of the urea cycle involves which of the following substances?

The conversion of isocitrate to α-ketoglutarate in step 3 of the citric acid cycle actually occurs by the two-step process shown below.What is true about step 3a?

Which of the following best describes the function of NAD+ and FAD in catabolic pathways?

Which organelle in the cytoplasm of the cell is the energy-producing factory of the cell?

Which correctly represents the products that result from the complete oxidation of an acetyl group in the citric acid cycle?

What is the name of the first compound formed in the citric acid cycle, produced by the transfer of an acetyl group from acetyl CoA to oxaloacetate?

The Krebs cycle begins with an aldol condensation.

ATP synthase is a very large multi-lipid complex.

Which of the following compounds is a positive effector of the allosteric enzyme isocitrate dehydrogenase?

Which of the following substances serves as an intermediate through which all cellular energy sources are interconvertible?

What word is used to describe a pathway that functions in both degradative and biosynthetic reactions?

Which of the following compounds in high concentration inhibits the pyruvate dehydrogenase complex, the enzyme responsible for the reaction shown below?

How many molecules of ATP are produced by oxidative phosphorylation for each molecule of NADH produced in the citric acid cycle?

Chemistry:methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

Calculations, Chemical Changes, and the Chemical Equation

States of Matter- Gases, Liquids, and Solids

Solutions

Energy, Rate and Equilibrium

Acids and Bases

The Nucleus, Radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry- the Saturated Hydrocarbons

The Unsaturated Hydrocarbons- Alkenes, Alkynes, and Aromatics

Alcohols, Phenols, Thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Fatty Acid Metabolism

Filters

How many molecules of FADH₂ are produced by the complete oxidation of one acetyl group by the citric acid cycle?

What is the role of F₀ in the F₀F₁ complex used in oxidative phosphorylation?

Which of the following best describes the function of NAD⁺ and FAD in catabolic pathways?