Question 1

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 D

Question 2

Brown adipose tissue is partially responsible for generating heat in the young human body.

Accepted Answer

A) True 
 B)False  True

Question 3

Which of the following statements concerning E ° for an electron-transfer reaction is false ?

Accepted Answer

A)  It is measured by comparison with the partial pressure of oxygen in the bloodstream rather than 1 atmosphere pressure. 
B)  It is measured by comparison with a standard hydrogen electrode. 
C)  It is related to Δ G ° by a well known equation. 
D)  It cannot be determined for electron-transfer reactions involving coenzyme Q. 
A)  It is measured by comparison with the partial pressure of oxygen in the bloodstream rather than 1 atmosphere pressure. 
B)  It is measured by comparison with a standard hydrogen electrode. 
C)  It is related to Δ G ° by a well known equation. 
D)  It cannot be determined for electron-transfer reactions involving coenzyme Q. A

Question 4

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 5

The F1F0 complex is actually a transmembrane complex.

Accepted Answer

A) True 
 B)False

Question 6

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 7

The final reduced species in the electron transport chain is

Accepted Answer

A)  O2 
B)  H2O 
C)  cytochrome c 
D)  coenzyme Q 
E)  none of these 
A)  O2 
B)  H2O 
C)  cytochrome c 
D)  coenzyme Q 
E)  none of these

Question 8

The cytochrome that passes electrons directly to oxygen is

Accepted Answer

A)  the cytochrome a\a 3 complex. 
B)  cytochrome b . 
C)  cytochrome c . 
D)  cytochrome c 1. 
A)  the cytochrome a\a 3 complex. 
B)  cytochrome b . 
C)  cytochrome c . 
D)  cytochrome c 1.

Question 9

Depending on how NADH is shuttled from the cytoplasm into the mitochondria, different molar amounts of ATP will be synthesized as each NADH is oxidized.

Accepted Answer

A) True 
 B)False

Question 10

The P\O ratio refers to the number of moles of ATP produced for each mole of

Accepted Answer

A)  oxygen atoms consumed in electron transport 
B)  oxygen molecules consumed in electron transport 
C)  NADH reoxidized in electron transport 
D)  FADH2 reoxidized in electron transport 
A)  oxygen atoms consumed in electron transport 
B)  oxygen molecules consumed in electron transport 
C)  NADH reoxidized in electron transport 
D)  FADH2 reoxidized in electron transport

Question 11

Which of the following terms describes ATP synthesis in mitochondria?

Accepted Answer

A)  substrate-level phosphorylation 
B)  oxidative phosphorylation 
C)  photophosphorylation 
D)  none of these 
A)  substrate-level phosphorylation 
B)  oxidative phosphorylation 
C)  photophosphorylation 
D)  none of these

Question 12

Explain the formation of a proton gradient.

Accepted Answer

A proton gradient exists because the var

Question 13

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 14

The only reaction which actually uses molecular oxygen is catalyzed by

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 15

The only complex which actually uses molecular oxygen is

Accepted Answer

A)  Complex I. 
B)  Complex II. 
C)  Complex III. 
D)  Complex IV. 
E)  It is not known where oxygen is used. 
A)  Complex I. 
B)  Complex II. 
C)  Complex III. 
D)  Complex IV. 
E)  It is not known where oxygen is used.

Question 16

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.

Question 17

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

Accepted Answer

A)  FADH2; coenzyme Q; doesn't pump 
B)  FADH2; coenzyme Q; pumps 
C)  NADH; coenzyme Q; doesn't pump 
D)  NADH; coenzyme Q; pumps 
A)  FADH2; coenzyme Q; doesn't pump 
B)  FADH2; coenzyme Q; pumps 
C)  NADH; coenzyme Q; doesn't pump 
D)  NADH; coenzyme Q; pumps

Question 18

Which complex contains cytochrome oxidase?

Accepted Answer

A)  Complex I 
B)  Complex II 
C)  Complex III 
D)  Complex IV 
E)  It is not known where cytochrome oxidase is located. 
A)  Complex I 
B)  Complex II 
C)  Complex III 
D)  Complex IV 
E)  It is not known where cytochrome oxidase is located.

Question 19

Transition metals are especially important in electron transport, since they have variable oxidation states.

Accepted Answer

A) True 
 B)False

Question 20

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

Exam 20: Electron Transport and Oxidative Phosphorylation

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

Brown adipose tissue is partially responsible for generating heat in the young human body.

Which of the following statements concerning E ° for an electron-transfer reaction is false ?

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

The F1F0 complex is actually a transmembrane complex.

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

The final reduced species in the electron transport chain is

The cytochrome that passes electrons directly to oxygen is

Depending on how NADH is shuttled from the cytoplasm into the mitochondria, different molar amounts of ATP will be synthesized as each NADH is oxidized.

The P\O ratio refers to the number of moles of ATP produced for each mole of

Which of the following terms describes ATP synthesis in mitochondria?

Explain the formation of a proton gradient.

Which of the following is not true?

The only reaction which actually uses molecular oxygen is catalyzed by

The only complex which actually uses molecular oxygen is

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

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

Which complex contains cytochrome oxidase?

Transition metals are especially important in electron transport, since they have variable oxidation states.

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

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 the 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.

The F₁F₀ complex is actually a transmembrane complex.

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