Question 1

The energy released during mitochondrial electron transport processes is used to

Accepted Answer

A)   make ATP.
B)   pump protons across the membrane.
C)   heat the mitochondria.
D)   synthesize carbohydrates.E) A) and B)
F) A) and C)

Question 2

What is the effect of oligomycin, an ATP synthase inhibitor, on the mitochondrial oxidative phosphorylation pathway?

Accepted Answer

A)   The mitochondria cannot reduce NADH or make ATP.
B)   No proton gradient is formed, and no ATP is synthesized.
C)   Protons leak back into the cytoplasm.
D)   The proton gradient is formed, but no ATP synthesis can occur.E) C) and D)
F) A) and B)

Question 3

What is the cellular location of eukaryotic thermogenin (or uncoupling protein) ?

Accepted Answer

A)   mitochondrial inner membrane
B)   mitochondrial matrix
C)   cytoplasm
D)   both cytoplasm and mitochondrial matrixE) B) and C)
F) All of the above

Question 4

What would happen if mitochondria were treated with a proton gradient uncoupler, such as 2,4-dinitrophenol?

Accepted Answer

A)   Electron transfer would stop.
B)   Complex I would become reduced, and complexes III and IV would become oxidized.
C)   Protons would be pumped by the mitochondrial electron transport chain, although no ATP would be synthesized.
D)   Reducing equivalents, in the form of NADH, would no longer be consumed.E) All of the above
F) A) and D)

Question 5

What is the driving force for ATP synthesis by the ATP synthase enzyme?

Accepted Answer

A)   The electron transfers through the protein complexes.
B)   ADP + Pi  →\rightarrow→  ATP
C)   The oxidation of NADH to NAD+.
D)   The pH gradient across the inner mitochondrial membrane. E) C) and D)
F) B) and C)

Question 6

List the major enzymes and enzyme complexes in the oxidative phosphorylation pathway, which are required to couple FADH2 oxidation with ATP synthesis.

Accepted Answer

Complex II (succinate dehydrog...

Question 7

What best describes the driving force for ATP synthesis in the mitochondria?

Accepted Answer

A)   Electron transport from electron transport system complexes.
B)   The higher pH inside the mitochondria that results from electron transfer.
C)   The large drops in  Δ\DeltaΔ G resulting from electron transfer in the ETC.
D)   The substrate level phosphorylations of the TCA cycle and glycolysis. E) A) and C)
F) B) and C)

Question 8

Electrons from a succinate molecule can enter into the ETC and result in enough pumped protons to make how many ATPs?

Accepted Answer

A)   2.0
B)   1.5
C)   1.0
D)   2.5E) A) and D)
F) C) and D)

Question 9

In the mitochondrial electron transport system, the electron from NADH moves from __________ the mitochondria through the protein complexes to the
Mitochondria.

Accepted Answer

A)   outside; outside
B)   outside; inside
C)   inside; inside
D)   inside; outsideE) All of the above
F) C) and D)

Question 10

What enzyme uses the proton motive force for its driving force?

Accepted Answer

A)   complex IV
B)   ATP synthase
C)   complex III
D)   complex IE) A) and B)
F) B) and D)

Question 11

Identify the correct order of electron transfers in the electron transport chain starting from FADH2.

Accepted Answer

A)   complex I  →\rightarrow→  complex II  →\rightarrow→  complex III  →\rightarrow→  complex IV
B)   complex II  →\rightarrow→  complex III  →\rightarrow→ cytochrome c  →\rightarrow→  complex IV
C)   complex II  →\rightarrow→  coenzyme Q  →\rightarrow→ complex IV  →\rightarrow→  ATP synthase
D)   complex I  →\rightarrow→  coenzyme Q  →\rightarrow→  complex III  →\rightarrow→  complex IV E) A) and C)
F) All of the above

Question 12

The resting state of the three  β\betaβ  subunits in the ATP synthase enzyme is best described as

Accepted Answer

A)   one O, one L, and one T conformation.
B)   all in O conformations.
C)   all in L conformations.
D)   one L and two O conformations. E) A) and D)
F) A) and B)

Question 13

The structure of 2,4-dinitrophenol is shown below. Explain how it functions to uncouple a proton gradient across the mitochondrial membrane.

Accepted Answer

<img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> 2,4-dinitrophenol is nonpolar enough th...

Question 14

How many ATPs are produced from the complete metabolism of one glucose molecule, assuming that all resulting NADH and FADH2 is used by the electron transport chain and oxidative phosphorylation to make ATP?

Accepted Answer

A)   4
B)   16
C)   32
D)   102E) A) and C)
F) B) and C)

Question 15

What are the principle physiological electron donors for the mitochondrial electron transport pathway?

Accepted Answer

A)   FADH2 and NADH
B)   FADH2, NADH, and NADPH
C)   NADH only
D)   UQH2, NADH, and FADH2E) B) and C)
F) C) and D)

Question 16

ATP synthesis occurs

Accepted Answer

A)   on the outer mitochondrial membrane.
B)   at the ATP synthase complex after ADP and Pi are transported into the mitochondria.
C)   as a result of the leakage of H+ back out of the mitochondria.
D)   from the electron transfer reactions through complex IV.E) None of the above
F) C) and D)

Question 17

Which of the following is an electron carrier in the mitochondrial electron transport system?

Accepted Answer

A)   proton
B)   water
C)   quinone
D)   ATPE) None of the above
F) All of the above

Question 18

In yeast, it is estimated that approximately H+ are required by ATP synthase per ATP synthesized.

Accepted Answer

A)   1
B)   3
C)   9
D)   10E) A) and B)
F) None of the above

Question 19

The drug oligomycin inhibits ATP synthase by preventing protons from flowing through the enzyme. Oligomycin must bind to the __________ of ATP synthase.

Accepted Answer

A)   catalytic headpiece
B)   F1 subunit
C)   ATP binding site
D)   F0 subunit ofE) C) and D)
F) All of the above

Question 20

List the conformation types and the changes to the substrates in a single $\beta$subunit on the ATP synthase catalytic head piece during one 360o rotation of the rotor.

Accepted Answer

A <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> subunit begins in the O or open form,...

Exam 11: Oxidative Phosphorylation

What are the principle physiological electron donors for the mitochondrial electron transport pathway?

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Which of the following is an electron carrier in the mitochondrial electron transport system?

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Identify the correct order of electron transfers in the electron transport chain starting from FADH2.

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What best describes the driving force for ATP synthesis in the mitochondria?

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What is the driving force for ATP synthesis by the ATP synthase enzyme?

Correct AnswerverifiedShow Answer

Electrons from a succinate molecule can enter into the ETC and result in enough pumped protons to make how many ATPs?

Correct AnswerverifiedShow Answer

What is the cellular location of eukaryotic thermogenin (or uncoupling protein) ?

Correct AnswerverifiedShow Answer

The structure of 2,4-dinitrophenol is shown below. Explain how it functions to uncouple a proton gradient across the mitochondrial membrane.

Correct Answerverified 2,4-dinitrophenol is nonpolar enough th...View AnswerShow Answer

In yeast, it is estimated that approximately H+ are required by ATP synthase per ATP synthesized.

Correct AnswerverifiedShow Answer

How many ATPs are produced from the complete metabolism of one glucose molecule, assuming that all resulting NADH and FADH2 is used by the electron transport chain and oxidative phosphorylation to make ATP?

Correct AnswerverifiedShow Answer

In the mitochondrial electron transport system, the electron from NADH moves from __________ the mitochondria through the protein complexes to the Mitochondria.

Correct AnswerverifiedShow Answer

The resting state of the three β\betaβ subunits in the ATP synthase enzyme is best described as

Correct AnswerverifiedShow Answer

What would happen if mitochondria were treated with a proton gradient uncoupler, such as 2,4-dinitrophenol?

Correct AnswerverifiedShow Answer

ATP synthesis occurs

Correct AnswerverifiedShow Answer

List the conformation types and the changes to the substrates in a single β\betaβ subunit on the ATP synthase catalytic head piece during one 360o rotation of the rotor.

Correct AnswerverifiedA subunit begins in the O or open form,...View AnswerShow Answer

The drug oligomycin inhibits ATP synthase by preventing protons from flowing through the enzyme. Oligomycin must bind to the __________ of ATP synthase.

Correct AnswerverifiedShow Answer

What enzyme uses the proton motive force for its driving force?

Correct AnswerverifiedShow Answer

The energy released during mitochondrial electron transport processes is used to

Correct AnswerverifiedShow Answer

List the major enzymes and enzyme complexes in the oxidative phosphorylation pathway, which are required to couple FADH2 oxidation with ATP synthesis.

Correct AnswerverifiedComplex II (succinate dehydrog...View AnswerShow Answer

What is the effect of oligomycin, an ATP synthase inhibitor, on the mitochondrial oxidative phosphorylation pathway?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Identify the correct order of electron transfers in the electron transport chain starting from FADH₂.

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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
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2,4-dinitrophenol is nonpolar enough th...
View Answer

In yeast, it is estimated that approximately H⁺are required by ATP synthase per ATP synthesized.

Correct Answer
verified

How many ATPs are produced from the complete metabolism of one glucose molecule, assuming that all resulting NADH and FADH₂ is used by the electron transport chain and oxidative phosphorylation to make ATP?

Correct Answer
verified

Correct Answer
verified

The resting state of the three $\beta$ subunits in the ATP synthase enzyme is best described as

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

List the conformation types and the changes to the substrates in a single $\beta$ subunit on the ATP synthase catalytic head piece during one 360^orotation of the rotor.

Correct Answer
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A subunit begins in the O or open form,...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
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List the major enzymes and enzyme complexes in the oxidative phosphorylation pathway, which are required to couple FADH₂ oxidation with ATP synthesis.

Correct Answer
verified
Complex II (succinate dehydrog...
View Answer

Correct Answer
verified