Question 1

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

Accepted Answer

$\mathrm{C_6H_{12}O_6} + 6\mathrm{O_2} ightarrow 6\mathrm{CO_2} + 6\mathrm{H_2O} + 	ext{Energy}$

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

Accepted Answer

Oxygen ($\mathrm{O_2}$)

Question 4

What is the primary purpose of the Krebs cycle in cellular respiration?

Accepted Answer

To generate electron carriers (NADH and FADH$_2$) for the electron transport chain

Question 5

Which of the following statements about substrate-level phosphorylation is correct?

Accepted Answer

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

Question 6

In the reaction $\mathrm{C_6H_{12}O_6} + 6\mathrm{O_2} \rightarrow 6\mathrm{CO_2} + 6\mathrm{H_2O}$, which molecule is oxidized and which is reduced?

Accepted Answer

Glucose is oxidized; oxygen is reduced

Question 7

Which process in cellular respiration produces the most ATP per molecule of glucose?

Accepted Answer

Oxidative phosphorylation (electron transport chain and chemiosmosis)

Question 8

What is the role of NAD+ in cellular respiration?

Accepted Answer

It acts as an electron carrier, accepting electrons and becoming reduced to NADH

Question 9

Which of the following best explains why oxygen is considered a strong oxidizing agent in cellular respiration?

Accepted Answer

Oxygen is highly electronegative and pulls electrons toward itself

Question 10

During the energy investment phase of glycolysis, how many ATP molecules are consumed per glucose molecule?

Accepted Answer

2 ATP

Question 11

Which of the following is TRUE about glycolysis?

Accepted Answer

It occurs in the cytoplasm and does not require oxygen

Question 12

What is the main function of the electron transport chain in mitochondria?

Accepted Answer

To create a proton gradient across the inner mitochondrial membrane

Question 13

Which step in cellular respiration is responsible for the majority of carbon dioxide ($\mathrm{CO_2}$) production?

Accepted Answer

Krebs cycle

Question 14

If a cell is deprived of oxygen, which process will continue to produce ATP?

Accepted Answer

Glycolysis

Question 15

Which of the following statements about fermentation is correct?

Accepted Answer

Fermentation regenerates NAD+ so glycolysis can continue in the absence of oxygen

Question 16

What is the evolutionary significance of glycolysis?

Accepted Answer

It is a universal pathway found in nearly all organisms, indicating it evolved early in the history of life

Question 17

Which of the following best describes chemiosmosis in cellular respiration?

Accepted Answer

The use of a proton gradient to drive ATP synthesis via ATP synthase

Question 18

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

Accepted Answer

Oxidative phosphorylation

Question 19

Facultative anaerobes are able to survive in both the presence and absence of oxygen because:

Accepted Answer

They can use pyruvate for either fermentation or cellular respiration depending on oxygen availability

Question 20

Which of the following is a correct statement about the regulation of cellular respiration?

Accepted Answer

The rate of catabolism is regulated by the level of ATP through negative feedback mechanisms

Cellular Respiration: Mechanisms and Pathways

Study Guide - Practice Questions