Question 1

Which of the following best describes the overall chemical equation for aerobic cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6 O_2$ \rightarrow 6 CO_2$ + 6 H_2O$$

Question 2

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

Accepted Answer

Oxidative phosphorylation

Question 3

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

Accepted Answer

O$$_2$$

Question 4

A patient’s muscle cells are deprived of oxygen during intense exercise. Which process allows ATP production to continue under these conditions?

Accepted Answer

Lactic acid fermentation

Question 5

Which of the following statements about glycolysis is TRUE?

Accepted Answer

It produces ATP via substrate-level phosphorylation.

Question 6

If a cell is exposed to a toxin that inhibits ATP synthase, which of the following would be directly affected?

Accepted Answer

The synthesis of ATP from ADP and $$P_i$$ during oxidative phosphorylation

Question 7

Which of the following best explains why fermentation is less efficient than aerobic respiration?

Accepted Answer

Fermentation only produces ATP via substrate-level phosphorylation and does not fully oxidize glucose.

Question 8

Which enzyme is allosterically inhibited by high levels of ATP during glycolysis, thus regulating the pathway?

Accepted Answer

Phosphofructokinase

Question 9

A genetic mutation causes a defect in the carrier protein that transports pyruvate into the mitochondria. Which process would be directly impaired?

Accepted Answer

Breakdown of pyruvate to acetyl-CoA

Question 10

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

Accepted Answer

ATP is produced by the direct transfer of a phosphate group from a substrate to ADP.

Question 11

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

Accepted Answer

Oxygen is highly electronegative, allowing for a large difference in potential energy between NADH and $$O_2.$$

Question 12

In the absence of oxygen, which molecule accumulates and causes glycolysis to eventually stop if fermentation does not occur?

Accepted Answer

NADH

Question 13

Which of the following is a product of the citric acid cycle for each acetyl-CoA that enters the cycle?

Accepted Answer

3 NADH, 1 FADH$$_2$$, 1 ATP (or GTP), and 2 CO$$_2$$

Question 14

A patient is diagnosed with a mitochondrial disorder that impairs the electron transport chain. Which of the following would you expect to observe in their cells?

Accepted Answer

Increased reliance on glycolysis and fermentation for ATP production

Question 15

Which of the following best describes the role of the proton-motive force in cellular respiration?

Accepted Answer

It drives the synthesis of ATP by ATP synthase as protons flow down their gradient.

Question 16

Which of the following statements about the Warburg effect is correct?

Accepted Answer

Cancer cells preferentially use glycolysis even when oxygen is present.

Question 17

Which of the following is a key regulatory mechanism for the citric acid cycle?

Accepted Answer

Inhibition by high levels of ATP and NADH

Question 18

Which of the following best explains why facultative anaerobes can survive in both aerobic and anaerobic environments?

Accepted Answer

They can use either oxygen or another molecule as the final electron acceptor, or switch to fermentation.

Question 19

Which of the following is a direct consequence if the electron transport chain stops due to lack of a final electron acceptor?

Accepted Answer

NADH accumulates and NAD+ becomes depleted, halting glycolysis

Question 20

Which of the following best describes the fate of fatty acids during cellular respiration?

Accepted Answer

They are broken down by beta-oxidation to acetyl-CoA, which enters the citric acid cycle.

Cellular Respiration and Fermentation: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard