Q: Which of the following equations correctly represents the overall process of aerobic cellular respiration?

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} \rightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + \text{energy (ATP + heat)}$$

Question 1

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

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain (ETC), combining with electrons and H+ to form water.

Question 2

During glycolysis, what is the net gain of ATP and NADH per molecule of glucose?

Accepted Answer

2 ATP and 2 NADH

Question 3

Which process occurs in the mitochondrial matrix and results in the release of CO$$_2$$ and production of NADH?

Accepted Answer

Pyruvate oxidation

Question 4

What is the main function of the electron transport chain (ETC) in cellular respiration?

Accepted Answer

To create a proton (H$$^+) $$gradient across the inner mitochondrial membrane

Question 5

Why does NADH generally support more ATP production than FADH$$_2$$ during oxidative phosphorylation?

Accepted Answer

NADH donates electrons earlier in the ETC, allowing more protons to be pumped and more ATP to be generated.

Question 6

What is chemiosmosis in the context of cellular respiration?

Accepted Answer

The movement of H$$^+$$ ions back into the mitochondrial matrix through ATP synthase, driving the synthesis of ATP.

Question 7

If an inhibitor blocks the electron transport chain, what is the most likely immediate effect on cellular respiration?

Accepted Answer

NADH will accumulate, NAD$$^+$$ will decrease, and ATP output will fall.

Question 8

Which of the following best explains why inner mitochondrial membrane folds (cristae) are important for cellular respiration?

Accepted Answer

They increase surface area for ETC proteins and ATP synthase, enhancing ATP production.

Question 9

What is the primary purpose of fermentation in cells when oxygen is unavailable?

Accepted Answer

To regenerate NAD$$^+$$ from NADH, allowing glycolysis to continue.

Question 10

A muscle cell is deprived of oxygen during intense exercise. Which metabolic pathway will the cell rely on most for ATP production?

Accepted Answer

Lactic acid fermentation

Question 11

Which of the following would most likely result from a mutation that increases the number of cristae in mitochondria?

Accepted Answer

Increased ATP production due to more ETC and ATP synthase proteins.

Question 12

If the proton gradient across the inner mitochondrial membrane is weakened (proton leak), what is the most likely consequence?

Accepted Answer

Less ATP is made through ATP synthase and more energy is released as heat.

Question 13

Which of the following equations correctly represents the overall process of aerobic cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} ightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + 	ext{energy (ATP + heat)}$$

Question 14

Which stage of cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 15

A yeast cell is fermenting glucose in the absence of oxygen. What are the likely end products?

Accepted Answer

Ethanol and CO$$_2$$

Question 16

Which of the following best explains why cells may rely more heavily on alternative metabolic routes when glycolysis or pyruvate oxidation is blocked?

Accepted Answer

Less fuel reaches downstream pathways, so cells must use other sources for energy.

Question 17

Which of the following is a direct result of electron flow through the ETC?

Accepted Answer

Proton pumping from the mitochondrial matrix to the intermembrane space

Question 18

Which molecule is regenerated during fermentation to allow glycolysis to continue in the absence of oxygen?

Accepted Answer

NAD$$^+$$

Question 19

Which of the following would most likely occur if ATP synthase is inhibited?

Accepted Answer

ATP production would decrease significantly, even if the proton gradient is maintained.

Question 20

Which of the following best describes the coupling of electron transport and ATP synthesis in mitochondria?

Accepted Answer

The energy from electron transport is used to create a proton gradient, which drives ATP synthesis via ATP synthase.

Cellular Respiration: Mechanisms, Stages, and Regulation

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드