Question 1

Which of the following statements best describes the role of oxygen in cellular respiration?

Accepted Answer

Oxygen is reduced at the end of the electron transport chain to form water.

Question 2

During glycolysis, what is the net gain of ATP molecules produced per molecule of glucose?

Accepted Answer

$$2$$

Question 3

Which of the following best explains why fermentation is necessary in the absence of oxygen?

Accepted Answer

Fermentation regenerates NAD$$^+$$, allowing glycolysis to continue.

Question 4

A muscle cell is rapidly using ATP during intense exercise and oxygen is limited. Which pathway will the cell primarily use to generate ATP, and what byproduct will accumulate?

Accepted Answer

Lactic acid fermentation; lactate

Question 5

Which of the following is the correct sequence of metabolic pathways in aerobic cellular respiration?

Accepted Answer

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

Question 6

If a poison blocks the H$$^+$$ gradient across the inner mitochondrial membrane, which process will be directly inhibited?

Accepted Answer

Chemiosmosis

Question 7

Which of the following best describes the process of oxidative phosphorylation?

Accepted Answer

ATP synthase uses the energy from a proton gradient to convert ADP and Pi into ATP.

Question 8

Which of the following is an example of a redox reaction in cellular respiration?

Accepted Answer

Glucose is oxidized to carbon dioxide, and oxygen is reduced to water.

Question 9

In the citric acid cycle, what is the significance of oxaloacetate?

Accepted Answer

It is the molecule that combines with acetyl-CoA to begin the cycle.

Question 10

A genetic mutation causes a cell to lack the enzyme for feedback inhibition in glycolysis. What is the most likely consequence?

Accepted Answer

Glycolysis will continue even when ATP levels are high.

Question 11

Which of the following statements about ATP production in cellular respiration is correct?

Accepted Answer

The citric acid cycle produces the least amount of ATP.

Question 12

Which of the following best explains why prokaryotes can perform glycolysis but not the citric acid cycle in mitochondria?

Accepted Answer

Prokaryotes lack mitochondria and perform all steps in the cytoplasm.

Question 13

Which of the following is the correct chemical formula for glucose?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$}$$

Question 14

A yeast cell is placed in an anaerobic environment. Which metabolic pathway will it use to generate ATP, and what is the main byproduct?

Accepted Answer

Alcoholic fermentation; ethanol

Question 15

Which of the following best describes chemiosmosis in cellular respiration?

Accepted Answer

The use of a proton gradient to drive the synthesis of ATP from ADP and Pi.

Question 16

If a cell's mitochondria are damaged and cannot maintain a proton gradient, which process will be most directly affected?

Accepted Answer

ATP synthesis by ATP synthase

Question 17

Which of the following is a correct description of the products and location of pyruvate oxidation in eukaryotic cells?

Accepted Answer

Acetyl-CoA is produced in the mitochondrial matrix.

Question 18

Which of the following is an example of feedback inhibition in cellular respiration?

Accepted Answer

High ATP levels inhibit an early enzyme in glycolysis.

Question 19

A patient has a genetic disorder that prevents the regeneration of NAD$$^+$$ during fermentation. What is the most likely consequence for their muscle cells during intense exercise?

Accepted Answer

Glycolysis will stop due to lack of NAD$$^+.$$

Question 20

Which of the following best summarizes the total ATP yield from one molecule of glucose during aerobic cellular respiration?

Accepted Answer

$$30$$–$$32$$ ATP

Cellular Respiration: Pathways, Mechanisms, and Regulation

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