Question 1

The complex in the electron transport chain that does not have a direct link to coenzyme Q in some form is

Accepted Answer

A)  the succinate dehydrogenase complex. 
B)  Complex I. 
C)  cytochrome c oxidase. 
D)  Complex III. 
A)  the succinate dehydrogenase complex. 
B)  Complex I. 
C)  cytochrome c oxidase. 
D)  Complex III.

Question 2

Mitochondrial membranes can be fragmented into small vesicles which still synthesize ATP; intact mitochondria are not required.

Accepted Answer

A) True 
 B)False

Question 3

If a cyclist started a race and rode at a near maximum speed, which of the following fuel sources would be used up first?

Accepted Answer

A)  fat in the muscle cells 
B)  muscle glycogen 
C)  liver glycogen 
D)  muscle creatine-phosphate 
E)  all of these would be exhausted simultaneously 
A)  fat in the muscle cells 
B)  muscle glycogen 
C)  liver glycogen 
D)  muscle creatine-phosphate 
E)  all of these would be exhausted simultaneously

Question 4

Uncoupling in mitochondria refers to:

Accepted Answer

A)  Interruption of electron flow. 
B)  Stopping electron flow but not stopping ATP synthesis. 
C)  Stopping ATP synthesis but not stopping electron flow. 
D)  Blocking the electrons from NADH from entering the electron transport system. 
E)  All of these describe uncoupling. 
A)  Interruption of electron flow. 
B)  Stopping electron flow but not stopping ATP synthesis. 
C)  Stopping ATP synthesis but not stopping electron flow. 
D)  Blocking the electrons from NADH from entering the electron transport system. 
E)  All of these describe uncoupling.

Question 5

Complex IV of the electron transport chain oxidizes ____, reduces ____, and ____ protons in the process.

Accepted Answer

A)  coenzyme Q; cytochrome c; pumps 
B)  cytochrome c; coenzyme Q; pumps 
C)  cytochrome c; O2; doesn't pump 
D)  cytochrome c; O2; pumps 
A)  coenzyme Q; cytochrome c; pumps 
B)  cytochrome c; coenzyme Q; pumps 
C)  cytochrome c; O2; doesn't pump 
D)  cytochrome c; O2; pumps

Question 6

Evidence for chemiosmotic coupling as the mechanism for oxidative phosphorylation is based on the observation that

Accepted Answer

A)  mitochondrial membrane fragments without compartmentalization can carry out oxidative phosphorylation 
B)  submitochondrial preparations that contain closed vesicles can carry out oxidative phosphorylation 
C)  many different kinds of substances can serve as uncouplers 
D)  it has proved impossible to duplicate the process in model systems 
A)  mitochondrial membrane fragments without compartmentalization can carry out oxidative phosphorylation 
B)  submitochondrial preparations that contain closed vesicles can carry out oxidative phosphorylation 
C)  many different kinds of substances can serve as uncouplers 
D)  it has proved impossible to duplicate the process in model systems

Question 7

A characteristic of the glycerol phosphate shuttle is

Accepted Answer

A)  it shuttles NADH across the mitochondrial membrane to yield 5 ATP/NADH 
B)  it shuttles the electrons from NADH across the mitochondrial membrane to FADH2, yielding 5 ATP/NADH 
C)  it only operates efficiently at high levels of NADH 
D)  malate is a key component in the shuttle process 
A)  it shuttles NADH across the mitochondrial membrane to yield 5 ATP/NADH 
B)  it shuttles the electrons from NADH across the mitochondrial membrane to FADH2, yielding 5 ATP/NADH 
C)  it only operates efficiently at high levels of NADH 
D)  malate is a key component in the shuttle process

Question 8

Another name for Complex II in the electron transport chain is

Accepted Answer

A)  cytochrome c oxidase. 
B)  NADH-CoQ oxidoreductase. 
C)  cytochrome bc1 complex. 
D)  succinate-CoQ oxidoreductase. 
A)  cytochrome c oxidase. 
B)  NADH-CoQ oxidoreductase. 
C)  cytochrome bc1 complex. 
D)  succinate-CoQ oxidoreductase.

Question 9

Which of the following is not true?

Accepted Answer

A)  The synthesis of ATP in mitochondria is driven by a proton or pH gradient. 
B)  The synthesis of ATP is directly linked to the oxidation of NADH 
C)  The reoxidation of NADH and FADH2 indirectly creates a proton gradient that is involved in ATP synthesis 
D)  All of these are true 
A)  The synthesis of ATP in mitochondria is driven by a proton or pH gradient. 
B)  The synthesis of ATP is directly linked to the oxidation of NADH 
C)  The reoxidation of NADH and FADH2 indirectly creates a proton gradient that is involved in ATP synthesis 
D)  All of these are true

Question 10

Which of the following are located in the inner mitochondrial membrane?

Accepted Answer

A)  all the components of the citric acid cycle and the electron transport chain 
B)  all the components of the citric acid cycle but none of the components of the electron transport chain 
C)  all the components of the electron transport chain but none of the components of the citric acid cycle 
D)  all the components of the electron transport chain and one of the components of the citric acid cycle, namely the succinate dehydrogenase complex 
A)  all the components of the citric acid cycle and the electron transport chain 
B)  all the components of the citric acid cycle but none of the components of the electron transport chain 
C)  all the components of the electron transport chain but none of the components of the citric acid cycle 
D)  all the components of the electron transport chain and one of the components of the citric acid cycle, namely the succinate dehydrogenase complex

Question 11

In the Q cycle coenzyme Q takes part

Accepted Answer

A)  in the oxidized and reduced forms only. 
B)  in the oxidized, reduced, and semiquinone forms. 
C)  in the oxidized and semiquinone forms only. 
D)  in the reduced and semiquinone forms only. 
A)  in the oxidized and reduced forms only. 
B)  in the oxidized, reduced, and semiquinone forms. 
C)  in the oxidized and semiquinone forms only. 
D)  in the reduced and semiquinone forms only.

Question 12

Which complex of the electron transport chain does NOT contain an iron-sulfur cluster?

Accepted Answer

A)  Complex I 
B)  Complex II 
C)  Complex III 
D)  Complex IV 
A)  Complex I 
B)  Complex II 
C)  Complex III 
D)  Complex IV

Question 13

Chemiosmotic coupling was first proposed by Peter Mitchell, who won a Nobel Prize for his theory.

Accepted Answer

A) True 
 B)False

Question 14

Conformation changes in proteins are crucial in the synthesis of ATP in the mitochondria.

Accepted Answer

A) True 
 B)False

Question 15

How many electrons are required for the complete reduction of one molecule of oxygen gas?

Accepted Answer

A)  one 
B)  two 
C)  four 
D)  eight 
A)  one 
B)  two 
C)  four 
D)  eight

Question 16

Which of the following was not evidence that supported Mitchell's chemiosmotic coupling hypothesis?

Accepted Answer

A)  Closed vessicles were required. Phosphorylation did not occur in a completely soluble environment. 
B)  Vessicles could be prepared from mitochondria and the assymetric location of electron transport protein could be shown. 
C)  The existence of the pH gradient could be demonstrated 
D)  The transfer of electrons from complex I to oxygen was shown 
E)  none of these 
A)  Closed vessicles were required. Phosphorylation did not occur in a completely soluble environment. 
B)  Vessicles could be prepared from mitochondria and the assymetric location of electron transport protein could be shown. 
C)  The existence of the pH gradient could be demonstrated 
D)  The transfer of electrons from complex I to oxygen was shown 
E)  none of these

Question 17

When mitochondria are actively carrying out aerobic respiration

Accepted Answer

A)  the pH of the matrix is greater than the pH of the intermembrane space. 
B)  the pH of the matrix is less than the pH of the intermembrane space. 
C)  the pH of the matrix is about the same as the pH of the intermembrane space. 
D)  the pH of the matrix versus the intermembrane space has nothing to do with whether not aerobic respiration is occurring. 
A)  the pH of the matrix is greater than the pH of the intermembrane space. 
B)  the pH of the matrix is less than the pH of the intermembrane space. 
C)  the pH of the matrix is about the same as the pH of the intermembrane space. 
D)  the pH of the matrix versus the intermembrane space has nothing to do with whether not aerobic respiration is occurring.

Question 18

Which of the following complexes does not directly contribute to the production of ATP by pumping protons?

Accepted Answer

A)  Complex I. 
B)  Complex II. 
C)  Complex III. 
D)  Complex IV. 
E)  All four complexes pump protons. 
A)  Complex I. 
B)  Complex II. 
C)  Complex III. 
D)  Complex IV. 
E)  All four complexes pump protons.

Question 19

Another name for Complex III in the mitochondria is

Accepted Answer

A)  Cytochrome C oxidase. 
B)  NADH-CoQ reductase. 
C)  succinate-CoQ reductase. 
D)  Cytochrome A oxidase. 
E)  Cytochrome bc1 complex. 
A)  Cytochrome C oxidase. 
B)  NADH-CoQ reductase. 
C)  succinate-CoQ reductase. 
D)  Cytochrome A oxidase. 
E)  Cytochrome bc1 complex.

Question 20

How do uncoupling agents affect the electron transport chain and oxidative phosphorylation?

Accepted Answer

A)  They block the flow of electrons, so protons aren't pumped, and ATP synthesis ceases. 
B)  They remove electrons from the chain, so less protons are pumped, and ATP synthesis decreases. 
C)  They block the flow of protons through the ATP synthase, so ATP synthesis ceases. Electron flow and proton pumping are also halted as a result. 
D)  They provide an alternative path for protons to re-enter the mitochondrial matrix, so ATP synthesis decreases. Electron flow and proton pumping are not affected. 
A)  They block the flow of electrons, so protons aren't pumped, and ATP synthesis ceases. 
B)  They remove electrons from the chain, so less protons are pumped, and ATP synthesis decreases. 
C)  They block the flow of protons through the ATP synthase, so ATP synthesis ceases. Electron flow and proton pumping are also halted as a result. 
D)  They provide an alternative path for protons to re-enter the mitochondrial matrix, so ATP synthesis decreases. Electron flow and proton pumping are not affected.

Exam 20: Electron Transport and Oxidative Phosphorylation

The complex in the electron transport chain that does not have a direct link to coenzyme Q in some form is

Mitochondrial membranes can be fragmented into small vesicles which still synthesize ATP; intact mitochondria are not required.

If a cyclist started a race and rode at a near maximum speed, which of the following fuel sources would be used up first?

Uncoupling in mitochondria refers to:

Complex IV of the electron transport chain oxidizes ____, reduces ____, and ____ protons in the process.

Evidence for chemiosmotic coupling as the mechanism for oxidative phosphorylation is based on the observation that

A characteristic of the glycerol phosphate shuttle is

Another name for Complex II in the electron transport chain is

Which of the following is not true?

Which of the following are located in the inner mitochondrial membrane?

In the Q cycle coenzyme Q takes part

Which complex of the electron transport chain does NOT contain an iron-sulfur cluster?

Chemiosmotic coupling was first proposed by Peter Mitchell, who won a Nobel Prize for his theory.

Conformation changes in proteins are crucial in the synthesis of ATP in the mitochondria.

How many electrons are required for the complete reduction of one molecule of oxygen gas?

Which of the following was not evidence that supported Mitchell's chemiosmotic coupling hypothesis?

When mitochondria are actively carrying out aerobic respiration

Which of the following complexes does not directly contribute to the production of ATP by pumping protons?

Another name for Complex III in the mitochondria is

How do uncoupling agents affect the electron transport chain and oxidative phosphorylation?

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

Filters

Complex IV of the electron transport chain oxidizes , reduces , and protons in the process.