$$\mathrm{NADH} \rightarrow \mathrm{NAD}^+ + 2e^- + H^+$$ \\ \mathrm{FADH}_2 \rightarrow \mathrm{FAD} + 2e^- + 2H^+$

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2 \rightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} + \text{energy}$$

Question 1

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

Accepted Answer

Oxygen is the final electron acceptor in the electron transport chain, forming water.

Question 2

During which stage of cellular respiration is the majority of ATP produced?

Accepted Answer

Oxidative phosphorylation

Question 3

Which of the following equations correctly represents the oxidation of NADH and FADH$$_2 in $$the electron transport chain?

Accepted Answer

$$\mathrm{NADH} ightarrow \mathrm{NAD}^+ + 2e^- + H^+$$ \ \mathrm{FADH}_2 ightarrow \mathrm{FAD} + 2e^- + 2H^+$

Question 4

Which process occurs in the cytoplasm and does not require oxygen?

Accepted Answer

Glycolysis

Question 5

What is the main purpose of fermentation in the absence of oxygen?

Accepted Answer

To regenerate NAD$$^+ so $$glycolysis can continue

Question 6

Which of the following best explains why the citric acid cycle is considered a cycle?

Accepted Answer

It begins and ends with oxaloacetate, which is regenerated each turn.

Question 7

Which molecule carries the smallest amount of potential energy derived from glucose during cellular respiration?

Accepted Answer

ATP

Question 8

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by transferring a phosphate group from a substrate to ADP.

Question 9

Which of the following statements about β-oxidation is correct?

Accepted Answer

β-oxidation breaks down fatty acids into acetyl-CoA, NADH, and FADH$$_2.$$

Question 10

Which of the following best describes the flow of energy during cellular respiration?

Accepted Answer

Energy flows from glucose to electron carriers to the proton gradient to ATP.

Question 11

Which of the following is true regarding the regulation of cellular respiration?

Accepted Answer

High concentrations of ADP and NAD$$^+$$ stimulate glycolysis.

Question 12

Which of the following is a product of ethanol fermentation in yeast?

Accepted Answer

Ethanol and CO$$_2$$

Question 13

Which of the following best explains why glycolysis is considered an anaerobic process?

Accepted Answer

It does not require oxygen to proceed.

Question 14

Which of the following is the correct net equation for the oxidation of glucose during cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2 ightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} + 	ext{energy}$$

Question 15

Which of the following is true about the energy yield from the complete oxidation of one glucose molecule?

Accepted Answer

Most ATP is produced during oxidative phosphorylation.

Question 16

Which of the following best describes the function of ATP synthase?

Accepted Answer

It uses the energy of the proton gradient to convert ADP and Pi into ATP.

Question 17

Which of the following is a direct result of the electron transport chain?

Accepted Answer

Formation of a proton gradient across the inner mitochondrial membrane

Question 18

Which of the following statements about glycogen is correct?

Accepted Answer

Glycogen is a large, branched chain of glucose molecules attached to a central protein.

Question 19

Which of the following would most likely occur if the concentration of ADP in a cell increases?

Accepted Answer

Cellular respiration would speed up to produce more ATP.

Question 20

Which of the following is true regarding the fate of pyruvate in the absence of oxygen?

Accepted Answer

Pyruvate is reduced to lactic acid or ethanol, regenerating NAD$$^+.$$

Cellular Respiration: Harvesting Energy from Carbohydrates and Other Fuel Molecules

Study Guide - Practice Questions