Question 1

In what way is the reaction shown a key one in carbohydrate catabolism?

Accepted Answer

A) The reaction allows pyruvate to enter the citric acid cycle where it can be completely oxidized to CO2. 
B) The reaction represents the final step in aerobic respiration. 
C) The reaction is the only NADH producing reaction in the citric acid cycle. 
D) The reaction is the only decarboxylation reaction in the citric acid cycle. 
E) The reaction represents the only energy-producing reaction of the citric acid cycle. 
A) The reaction allows pyruvate to enter the citric acid cycle where it can be completely oxidized to CO2. 
B) The reaction represents the final step in aerobic respiration. 
C) The reaction is the only NADH producing reaction in the citric acid cycle. 
D) The reaction is the only decarboxylation reaction in the citric acid cycle. 
E) The reaction represents the only energy-producing reaction of the citric acid cycle.

Question 2

The acetyl group of acetyl CoA is transferred to oxaloacetate by the enzyme citrate synthase.

Accepted Answer

A) True 
 B)False

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

Which statement concerning the stages of catabolism is FALSE?

Accepted Answer

A) The primary function of digestion is to break down large food molecules into smaller ones that can be absorbed by the blood. 
B) The primary function of Stage II is to produce NADH and FADH2 for the citric acid cycle. 
C) Most food molecules enter Stage III of catabolism in the form of acetyl CoA. 
D) The primary function of the citric acid cycle in Stage III is to oxidize acetyl groups to CO2,and provide reduced coenzymes for the synthesis of ATP. 
E) The primary function of electron transport and oxidative phosphorylation is to oxidize NADH and FADH2,and provide energy for the production of ATP. 
A) The primary function of digestion is to break down large food molecules into smaller ones that can be absorbed by the blood. 
B) The primary function of Stage II is to produce NADH and FADH2 for the citric acid cycle. 
C) Most food molecules enter Stage III of catabolism in the form of acetyl CoA. 
D) The primary function of the citric acid cycle in Stage III is to oxidize acetyl groups to CO2,and provide reduced coenzymes for the synthesis of ATP. 
E) The primary function of electron transport and oxidative phosphorylation is to oxidize NADH and FADH2,and provide energy for the production of ATP.

Question 5

The mitochondria are aerobic.

Accepted Answer

A) True 
 B)False

Question 6

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 7

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 8

Where in the body does the degradation of amino acids occur?

Accepted Answer

A) stomach 
B) small intestine 
C) liver 
D) adipose tissue 
E) cytoplasm 
A) stomach 
B) small intestine 
C) liver 
D) adipose tissue 
E) cytoplasm

Question 9

In which stage of metabolism is the most energy in the form of ATP produced?

Accepted Answer

A) oxidative phosphorylation 
B) digestion of food molecules 
C) transcription pathway 
D) citric acid cycle 
E) glycolysis 
A) oxidative phosphorylation 
B) digestion of food molecules 
C) transcription pathway 
D) citric acid cycle 
E) glycolysis

Question 10

In addition to glutamate,what other compound is produced in the transamination reaction in which alanine and α-ketoglutarate react?

Accepted Answer

A) CH3CH2COO− 
B) CO2 
C) 
  
D) 
  
E) 
  
A) CH3CH2COO− 
B) CO2 
C) 
  
D) 
  
E)

Question 11

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

Question 12

The acetyl group is an important part of cellular metabolism.Which of the following is the acetyl group?

Accepted Answer

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

Question 13

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 14

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 15

FADH2 is a less powerful reducing agent (electron donor)than NADH.What is the consequence of this in oxidative phosphorylation?

Accepted Answer

A) FADH2 requires more steps than NADH does in electron transport to become oxidized. 
B) The electrons from FADH2 enter electron transport at a higher energy level than the electrons from NADH. 
C) A molecule of FADH2 is only capable of producing 2 molecules of ATP,while a molecule of NADH is capable of producing 3 molecules of ATP. 
D) Oxidation of FADH2 occurs in the cytoplasm of the cell,while oxidation of NADH occurs in the mitochondria. 
E) FADH2 can only donate 1 phosphate group to ATP,while NADH can donate 2 phosphate groups to ATP.  
A) FADH2 requires more steps than NADH does in electron transport to become oxidized. 
B) The electrons from FADH2 enter electron transport at a higher energy level than the electrons from NADH. 
C) A molecule of FADH2 is only capable of producing 2 molecules of ATP,while a molecule of NADH is capable of producing 3 molecules of ATP. 
D) Oxidation of FADH2 occurs in the cytoplasm of the cell,while oxidation of NADH occurs in the mitochondria. 
E) FADH2 can only donate 1 phosphate group to ATP,while NADH can donate 2 phosphate groups to ATP.

Question 16

The oxidative reactions of metabolism provide for most ATP production.In what specific part of the cell do these reactions occur?

Accepted Answer

A) nucleus 
B) ribosome 
C) mitochondria 
D) mitochondrial membrane 
E) None of the choices are correct. 
A) nucleus 
B) ribosome 
C) mitochondria 
D) mitochondrial membrane 
E) None of the choices are correct.

Question 17

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 18

What alternative name of the citric acid cycle is used in honor of the scientist who first proposed the steps of the cycle?

Accepted Answer

A) Cori cycle 
B) Embden-Meyerhof pathway 
C) Krebs cycle 
D) Watson-Crick cycle 
E) Chargaff cycle 
A) Cori cycle 
B) Embden-Meyerhof pathway 
C) Krebs cycle 
D) Watson-Crick cycle 
E) Chargaff cycle

Question 19

The enzyme fumarase catalyzes the hydration of fumarate in step 7 of the citric acid cycle.What is the product of this reaction?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) HOCH2CH2OH 
A) 
  
B) 
  
C) 
  
D) 
  
E) HOCH2CH2OH

Question 20

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%

Exam 22: Aerobic Respiration and Energy Production

In what way is the reaction shown a key one in carbohydrate catabolism?

The acetyl group of acetyl CoA is transferred to oxaloacetate by the enzyme citrate synthase.

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

Which statement concerning the stages of catabolism is FALSE?

The mitochondria are aerobic.

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

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?

Where in the body does the degradation of amino acids occur?

In which stage of metabolism is the most energy in the form of ATP produced?

In addition to glutamate,what other compound is produced in the transamination reaction in which alanine and α-ketoglutarate react?

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

The acetyl group is an important part of cellular metabolism.Which of the following is the acetyl group?

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

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

FADH2 is a less powerful reducing agent (electron donor)than NADH.What is the consequence of this in oxidative phosphorylation?

The oxidative reactions of metabolism provide for most ATP production.In what specific part of the cell do these reactions occur?

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

What alternative name of the citric acid cycle is used in honor of the scientist who first proposed the steps of the cycle?

The enzyme fumarase catalyzes the hydration of fumarate in step 7 of the citric acid cycle.What is the product of this reaction?

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?

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 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

FADH₂ is a less powerful reducing agent (electron donor)than NADH.What is the consequence of this in oxidative phosphorylation?