Question 1

Label the locations of$\alpha$, $\beta$, $\gamma$, and c, and the F₀ and F₁ subunits on the following ATP synthase enzyme.

Accepted Answer

The answer of Label the locations of$\alpha$, $\beta$, $\gamma$, and...

Question 2

Which of the following is NOT a part of oxidative phosphorylation?

Accepted Answer

A)  NADH is oxidized to NAD+. 
B)  O2 is reduced to H2O. 
C)  Electrons from O2 are transferred to ATP. 
D)  The pumping of protons is coupled with the formation of ATP.

Question 3

Studies of the inner mitochondrial membrane reveal its composition to be approximately 20% lipid bilayer and 80% protein. What is true of these proteins?

Accepted Answer

A)  Abundant collagen proteins form connective tissues to strengthen the membrane against the pH gradient. 
B)  High levels of proteins are required to metabolize glucose in the glycolysis pathway for rapid energy production. 
C)  The proteins form highly folded cristae structures. 
D)  The proteins are largely electron transport complexes and ATP synthase enzymes.

Question 4

Inhibitors of the electron transport system, such as cyanide (CN - ) and carbon monoxide (CO), inhibit complex IV by binding to the heme iron cofactor. What is the resulting effect on oxidative phosphorylation?

Accepted Answer

A)  Electrons pass through the electron transport system, but no protons are pumped. 
B)  Protons are pumped, but no electron transport occurs. 
C)  The electron transport system occurs normally, but no ATP is synthesized. 
D)  Electron transport is disabled, and no protons are pumped.

Question 5

Describe the process by which proton flow through the c subunits forces the rotation of the ATP synthase spindle in the mitochondrial membrane. Please include the roles of aspartic acid residues and the half-channels in your description.

Accepted Answer

The answer of Describe the process by which proton flow...

Question 6

Use the structure of the oxidized coenzyme Q (ubiquinone) shown below and draw the two-electron reduced form.

Accepted Answer

The answer of Use the structure of the oxidized coenzyme...

Question 7

Which one of the following is involved in the flow of electrons from NADH through the electron transport system to molecular oxygen (O2)?

Accepted Answer

A)  ATP synthase 
B)  complex II 
C)  complex III 
D)  ATP

Question 8

The first enzyme in the electron transport system is referred to as complex I, otherwise known as

Accepted Answer

A)  ATP synthase. 
B)  NADH-ubiquinone oxidoreductase. 
C)  succinate dehydrogenase. 
D)  cytochrome c oxidase.

Question 9

Which is the only electron carrier in the electron transport system that is not embedded in a membrane?

Accepted Answer

A)  ATP 
B)  cytochrome c 
C)  coenzyme Q 
D)  complex I

Question 10

Which one of the following statements about the glycerol phosphate shuttle is true?

Accepted Answer

A)  It involves the transfer of electrons from cytoplasmic NADH to dihydroxyacetone phosphate (DHAP) to yield glycerol phosphate. 
B)  It is more efficient than the malate aspartate shuttle. 
C)  NADH produced in the cytoplasm by glycolysis ultimately leads to NADH in mitochondria. 
D)  Glycerol phosphate diffuses into the mitochondria.

Question 11

Mitochondria

Accepted Answer

A)  selectively transport molecules from the cytoplasm to the intermembrane space. 
B)  maintain a pH gradient across the inner mitochondrial membrane. 
C)  are found one per cell. 
D)  have a matrix that is continuous with the cytoplasm.

Question 12

A characteristic of complex III is that it

Accepted Answer

A)  transports electrons from cytochrome c to complex IV. 
B)  is reduced by FADH2. 
C)  uses the Q cycle mechanism to oxidize ubiquinone. 
D)  participates in electron transfer when the donor is NADH but not when the donor is succinate (or FADH2).

Question 13

The electron transport complexes found in the electron transport system

Accepted Answer

A)  contain multiple electron transfer cofactors that facilitate electron transfer through the complexes. 
B)  are bound to the outer mitochondrial membrane. 
C)  pump protons from outside the mitochondria to the mitochondrial matrix on electron transfer. 
D)  absorb light energy that results in electron transfer.

Question 14

What active site cofactor is found in the electron transport system protein called cytochrome c?

Accepted Answer

A)  heme 
B)  FeS cluster 
C)  Flavin 
D)  quinone

Question 15

What is the fate of NADH after it donates its electrons to the electron transport system?

Accepted Answer

A)  NAD+ is excreted from the cell and sent to the liver for final degradation. 
B)  NADH is used for cellular biosynthesis. 
C)  NAD+ is re-reduced by the TCA cycle or glycolysis and returns to electron transport system, where the process is repeated. 
D)  NAD+ is fed into the TCA cycle for oxidation of CO2.

Question 16

What happens to patients given the proton gradient uncoupler 2,4-dinitrophenol?

Accepted Answer

A)  They undergo rapid decrease in body temperature as a result of lack of mitochondrial electron transport. 
B)  They experience lower cellular pH as a result of rapid proton gradient dissipation. 
C)  Their mitochondrial membranes fail as a result of rapid proton gradient release. 
D)  Their body temperatures rise as a result of heat release from gradient uncoupling.

Question 17

Draw a diagram of the mitochondrion and indicate which side of the organelle has a net positive charge and which side has a net negative charge as a result of proton pumping.

Accepted Answer

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Question 18

Which mechanism is the most efficient at moving NADH equivalents from the cytoplasm into the mitochondria?

Accepted Answer

A)  citrate shuttle 
B)  malate-aspartate shuttle 
C)  glyoxylate shunt 
D)  glycerol phosphate shuttle

Question 19

Submitochondrial particles are inside-out pieces of the inner mitochondrial membrane formed through the sonication of mitochondria. Draw a diagram of these inside-out particles clearly showing (A) where electron transport from NADH occurs, (B) the direction of proton pumping, (C) the location of ATP synthesis, and (D) where O₂ reacts.

Accepted Answer

The answer of Submitochondrial particles are inside-out pieces of the...

Exam 11: Oxidative Phosphorylation

Label the locations of $\alpha$ , $\beta$ , $\gamma$ , and c, and the F₀ and F₁ subunits on the following ATP synthase enzyme. $Label the locations of \alpha , \beta , \gamma , and c, and the F<sub>0</sub> and F<sub>1</sub> subunits on the following ATP synthase enzyme.$

Which of the following is NOT a part of oxidative phosphorylation?

Studies of the inner mitochondrial membrane reveal its composition to be approximately 20% lipid bilayer and 80% protein. What is true of these proteins?

Inhibitors of the electron transport system, such as cyanide (CN ^- ) and carbon monoxide (CO) , inhibit complex IV by binding to the heme iron cofactor. What is the resulting effect on oxidative phosphorylation?

Describe the process by which proton flow through the c subunits forces the rotation of the ATP synthase spindle in the mitochondrial membrane. Please include the roles of aspartic acid residues and the half-channels in your description.

Use the structure of the oxidized coenzyme Q (ubiquinone) shown below and draw the two-electron reduced form.

Which one of the following is involved in the flow of electrons from NADH through the electron transport system to molecular oxygen (O₂) ?

The first enzyme in the electron transport system is referred to as complex I, otherwise known as

Which is the only electron carrier in the electron transport system that is not embedded in a membrane?

Which one of the following statements about the glycerol phosphate shuttle is true?

Mitochondria

A characteristic of complex III is that it

The electron transport complexes found in the electron transport system

What active site cofactor is found in the electron transport system protein called cytochrome c?

What is the fate of NADH after it donates its electrons to the electron transport system?

What happens to patients given the proton gradient uncoupler 2,4-dinitrophenol?

Draw a diagram of the mitochondrion and indicate which side of the organelle has a net positive charge and which side has a net negative charge as a result of proton pumping.

Which mechanism is the most efficient at moving NADH equivalents from the cytoplasm into the mitochondria?

Exam 11: Oxidative Phosphorylation

Label the locations of α\alphaα , β\betaβ , γ\gammaγ , and c, and the F0 and F1 subunits on the following ATP synthase enzyme.

Which of the following is NOT a part of oxidative phosphorylation?

Studies of the inner mitochondrial membrane reveal its composition to be approximately 20% lipid bilayer and 80% protein. What is true of these proteins?

Inhibitors of the electron transport system, such as cyanide (CN - ) and carbon monoxide (CO) , inhibit complex IV by binding to the heme iron cofactor. What is the resulting effect on oxidative phosphorylation?

Describe the process by which proton flow through the c subunits forces the rotation of the ATP synthase spindle in the mitochondrial membrane. Please include the roles of aspartic acid residues and the half-channels in your description.

Use the structure of the oxidized coenzyme Q (ubiquinone) shown below and draw the two-electron reduced form.

Which one of the following is involved in the flow of electrons from NADH through the electron transport system to molecular oxygen (O2) ?

The first enzyme in the electron transport system is referred to as complex I, otherwise known as

Which is the only electron carrier in the electron transport system that is not embedded in a membrane?

Which one of the following statements about the glycerol phosphate shuttle is true?

Mitochondria

A characteristic of complex III is that it

The electron transport complexes found in the electron transport system

What active site cofactor is found in the electron transport system protein called cytochrome c?

What is the fate of NADH after it donates its electrons to the electron transport system?

What happens to patients given the proton gradient uncoupler 2,4-dinitrophenol?

Draw a diagram of the mitochondrion and indicate which side of the organelle has a net positive charge and which side has a net negative charge as a result of proton pumping.

Which mechanism is the most efficient at moving NADH equivalents from the cytoplasm into the mitochondria?

Label the locations of $\alpha$ , $\beta$ , $\gamma$ , and c, and the F₀ and F₁ subunits on the following ATP synthase enzyme. $Label the locations of \alpha , \beta , \gamma , and c, and the F<sub>0</sub> and F<sub>1</sub> subunits on the following ATP synthase enzyme.$

Inhibitors of the electron transport system, such as cyanide (CN ^- ) and carbon monoxide (CO) , inhibit complex IV by binding to the heme iron cofactor. What is the resulting effect on oxidative phosphorylation?

Which one of the following is involved in the flow of electrons from NADH through the electron transport system to molecular oxygen (O₂) ?