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

To regenerate $$\text{NAD}^+ so $$glycolysis can continue

They are released as $$\text{CO}_2.$$

Question 1

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

Accepted Answer

$$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2 ightarrow 6 	ext{CO}_2 + 6 	ext{H}_2	ext{O} + 	ext{Energy}$$

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

$$	ext{O}_2$$

Question 4

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

Accepted Answer

To regenerate $$	ext{NAD}^+ so $$glycolysis can continue

Question 5

Which of the following statements about redox reactions in cellular respiration is correct?

Accepted Answer

Glucose is oxidized and oxygen is reduced.

Question 6

In the citric acid cycle, what happens to the carbons originally present in glucose?

Accepted Answer

They are released as $$	ext{CO}_2.$$

Question 7

Which process directly produces ATP by transferring a phosphate group from a substrate molecule to ADP?

Accepted Answer

Substrate-level phosphorylation

Question 8

A poison that blocks the function of ATP synthase would directly affect which process?

Accepted Answer

The synthesis of ATP from ADP and $$P_i$$ during chemiosmosis

Question 9

Which of the following is a correct description of the energy yield from one molecule of glucose during cellular respiration?

Accepted Answer

About 32 ATP are produced

Question 10

Why are organic molecules with many hydrogen atoms excellent fuels for cellular respiration?

Accepted Answer

Hydrogen atoms have high potential energy that can be released when transferred to oxygen.

Question 11

Which of the following best explains why the electron transport chain is necessary in cellular respiration?

Accepted Answer

It breaks the fall of electrons to oxygen into several energy-releasing steps, allowing controlled ATP synthesis.

Question 12

In lactic acid fermentation, what is the fate of pyruvate?

Accepted Answer

It is reduced to lactate.

Question 13

Which of the following is NOT a product of the citric acid cycle per turn?

Accepted Answer

Pyruvate

Question 14

What is the role of oxygen in aerobic cellular respiration?

Accepted Answer

It serves as the final electron acceptor in the electron transport chain.

Question 15

Which of the following best describes chemiosmosis in mitochondria?

Accepted Answer

The use of a proton gradient to drive the synthesis of ATP

Question 16

If a cell is deprived of oxygen, which process will immediately stop?

Accepted Answer

Electron transport chain

Question 17

Which of the following is a correct sequence of energy flow during cellular respiration?

Accepted Answer

Glucose $$\rightarrow$$ NADH $$\rightarrow$$ Electron transport chain $$\rightarrow$$ Proton-motive force $$\rightarrow$$ ATP

Question 18

Which of the following is true about substrate-level phosphorylation?

Accepted Answer

It involves the direct transfer of a phosphate group to ADP from a substrate.

Question 19

In alcohol fermentation, what is the final electron acceptor?

Accepted Answer

Acetaldehyde

Question 20

Which of the following is a real-world example of anaerobic respiration?

Accepted Answer

Bacteria using sulfate ions ($$	ext{SO}_4$$^{2-}$$) as a final electron acceptor, producing hydrogen sulfide ($$	ext{H}_2	ext{S}$$)

Cellular Respiration and Fermentation: Mechanisms of Energy Harvest in Cells

Study Guide - Practice Questions