Question 1

Which of the following best describes the role of the electron transport chain (ETC) in cellular respiration?

Accepted Answer

It oxidizes NADH and FADH2, transferring electrons to oxygen and generating a proton gradient.

Question 2

During oxidative phosphorylation, what is the primary source of energy used to synthesize ATP?

Accepted Answer

The proton gradient across the inner mitochondrial membrane.

Question 3

Which equation correctly represents the formation of ATP by ATP synthase during cellular respiration?

Accepted Answer

$$ \mathrm{ADP} + \mathrm{P_i} \rightarrow \mathrm{ATP} $$

Question 4

What would happen to cellular respiration if oxygen were suddenly unavailable to a human muscle cell?

Accepted Answer

The electron transport chain would stop, NAD+ would not be regenerated, and fermentation would begin.

Question 5

Which molecule acts as the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen ($$ \mathrm{O_2$} )$$

Question 6

Why does fermentation produce much less ATP per glucose molecule than aerobic respiration?

Accepted Answer

Fermentation does not utilize the electron transport chain or oxidative phosphorylation.

Question 7

Which of the following is a correct description of lactic acid fermentation in human muscle cells?

Accepted Answer

Pyruvate accepts electrons from NADH, forming lactate and regenerating NAD+.

Question 8

Which of the following statements about ATP synthase is TRUE?

Accepted Answer

It is a membrane-bound enzyme that uses the flow of protons to phosphorylate ADP.

Question 9

In the electron transport chain, what is the function of cytochrome c?

Accepted Answer

It transfers electrons between complexes III and IV.

Question 10

Which of the following best explains why facultative anaerobes can survive in both oxygen-rich and oxygen-poor environments?

Accepted Answer

They can switch between aerobic respiration and fermentation depending on oxygen availability.

Question 11

Which process is responsible for regenerating NAD+ in the absence of oxygen?

Accepted Answer

Fermentation.

Question 12

What is the main difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Substrate-level phosphorylation directly transfers a phosphate group from a substrate to ADP, while oxidative phosphorylation uses a proton gradient to drive ATP synthesis.

Question 13

Which of the following equations represents the net ATP yield from fermentation of one glucose molecule?

Accepted Answer

$$ \mathrm{Glucose} \rightarrow 2 \mathrm{ATP} + 2 \mathrm{Lactate} $$

Question 14

Which of the following is a consequence of a blocked electron transport chain in mitochondria?

Accepted Answer

NADH and FADH2 accumulate, and NAD+ is depleted.

Question 15

In alcohol fermentation, which molecule is converted to ethanol?

Accepted Answer

Pyruvate.

Question 16

Which of the following best describes the chemiosmotic hypothesis?

Accepted Answer

A proton gradient across a membrane drives ATP synthesis via ATP synthase.

Question 17

Which of the following is TRUE regarding anaerobic respiration in prokaryotes?

Accepted Answer

It uses alternative electron acceptors such as nitrate or sulfate.

Question 18

If a poison blocks the proton channel of ATP synthase, what is the most immediate effect on cellular respiration?

Accepted Answer

ATP production by oxidative phosphorylation will stop.

Question 19

Which of the following best explains why oxygen is the most effective final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen has the highest redox potential, allowing for maximum energy release.

Cellular Respiration: Electron Transport Chain and Fermentation

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드