Question 1

Which compartment of the mitochondrion is the site of the citric acid cycle, and what is a key product of this cycle that is used in the electron transport chain?

Accepted Answer

Matrix; NADH

Question 2

During aerobic respiration, what is the correct sequence of events for the complete oxidation of glucose?

Accepted Answer

Glycolysis → Pyruvate Oxidation → Citric Acid Cycle → Electron Transport Chain

Question 3

Which of the following best explains why the inner mitochondrial membrane is critical for ATP synthesis?

Accepted Answer

It maintains a proton gradient used by ATP synthase.

Question 4

What is the role of oxygen in the electron transport chain?

Accepted Answer

It is the terminal electron acceptor, forming water.

Question 5

Which equation correctly represents the oxidation of NADH in the electron transport chain?

Accepted Answer

$$\mathrm{NADH} + \mathrm{H}^+ + \frac{1}{2} \mathrm{O}_2 \rightarrow \mathrm{NAD}^+ + \mathrm{H}_2\mathrm{O}$$

Question 6

A mutation impairs the function of Complex III in the electron transport chain. Which of the following is a likely consequence?

Accepted Answer

Reduced proton pumping and decreased ATP synthesis

Question 7

Which shuttle system is responsible for transferring electrons from cytosolic NADH into the mitochondrial matrix?

Accepted Answer

Malate-Aspartate Shuttle

Question 8

How many ATP molecules are theoretically produced from the oxidation of one NADH via the electron transport chain?

Accepted Answer

2.5 to 3

Question 9

Which of the following best describes the function of the F$$_0F$_1$$ ATP synthase complex?

Accepted Answer

It synthesizes ATP using the energy from the proton gradient.

Question 10

Which of the following is NOT a product of the citric acid cycle per turn (per acetyl CoA)?

Accepted Answer

2 ATP

Question 11

A patient has a defect in the mitochondrial pyruvate carrier (MPC). Which process would be directly affected?

Accepted Answer

Transport of pyruvate into the mitochondrial matrix

Question 12

Which of the following statements about the electron transport chain is correct?

Accepted Answer

The order of electron carriers is determined by their standard reduction potentials.

Question 13

Which metabolic process occurs in the mitochondrial matrix and is responsible for the majority of CO$$_2$$ production during aerobic respiration?

Accepted Answer

Citric Acid Cycle

Question 14

Which of the following best explains why the maximum theoretical ATP yield is rarely achieved in cells?

Accepted Answer

Some protons leak across the membrane or are used for other processes.

Question 15

Which of the following is a correct description of the binding change model for ATP synthesis?

Accepted Answer

The β subunits cycle through loose, tight, and open conformations to synthesize ATP.

Question 16

Which of the following is a direct result of the oxidation of FADH$$_2 in $$the electron transport chain?

Accepted Answer

Fewer protons are pumped compared to NADH oxidation.

Question 17

Which of the following best describes the role of coenzyme Q (ubiquinone) in the electron transport chain?

Accepted Answer

It acts as a mobile electron carrier between Complex I/II and Complex III.

Question 18

A drug inhibits the function of ATP synthase. What would be the immediate effect on the proton gradient and ATP production?

Accepted Answer

The proton gradient would increase and ATP production would decrease.

Question 19

Which of the following processes is NOT localized in the mitochondrial matrix?

Accepted Answer

Electron transport

Ch. 10: Aerobic Respiration-Cellular Energy Metabolism and Mitochondrial Function

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