Question 1

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

The direct transfer of a phosphate group from a substrate molecule to ADP, forming ATP.

Question 2

Which of the following is the correct summary equation for 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 3

During the process of oxidative phosphorylation, which of the following best describes the role of chemiosmosis?

Accepted Answer

It uses the energy of a proton gradient to drive the synthesis of ATP via ATP synthase.

Question 4

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

Accepted Answer

Glucose is oxidized; oxygen is reduced.

Question 5

Which of the following statements about the electron transport chain (ETC) is correct?

Accepted Answer

The ETC transfers electrons from NADH and FADH$$_2 to $$oxygen, releasing energy used to pump protons across the inner mitochondrial membrane.

Question 6

Which of the following is a metabolic intermediate?

Accepted Answer

Citrate, formed during the Krebs cycle.

Question 7

Where in the cell does the conversion of pyruvate to acetyl-CoA occur?

Accepted Answer

In the mitochondrial matrix.

Question 8

Which of the following best explains why the actual ATP yield per glucose is often less than the theoretical maximum?

Accepted Answer

Some protons leak across the mitochondrial membrane, and energy is used for other cellular processes.

Question 9

Which of the following is NOT a product of fermentation in human muscle cells?

Accepted Answer

Ethanol

Question 10

Which of the following statements correctly compares fermentation and cellular respiration?

Accepted Answer

Fermentation produces less ATP per glucose than cellular respiration.

Question 11

Which of the following is the main role of electron carriers such as NAD+ and FAD in cellular respiration?

Accepted Answer

They accept electrons during redox reactions and transfer them to the electron transport chain.

Question 12

A patient is diagnosed with a mitochondrial disorder that impairs ATP synthase. Which process would be most directly affected?

Accepted Answer

Chemiosmosis during oxidative phosphorylation.

Question 13

Which of the following correctly lists the three main reaction sequences of cellular respiration in order?

Accepted Answer

Glycolysis, pyruvate oxidation (transition step), Krebs cycle

Question 14

Which of the following best describes the fate of proteins used as energy sources in cellular respiration?

Accepted Answer

They are broken down into amino acids, which are deaminated and enter the Krebs cycle as intermediates.

Question 15

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

Accepted Answer

Glycolysis

Question 16

Which of the following is a correct statement about the location of cellular respiration processes in eukaryotic cells?

Accepted Answer

Glycolysis occurs in the cytoplasm, while the Krebs cycle and ETC occur in the mitochondria.

Question 17

Which of the following best explains why fats yield more ATP per gram than carbohydrates during cellular respiration?

Accepted Answer

Fats have more hydrogen atoms, leading to more electrons for the electron transport chain.

Question 18

Which of the following is true regarding the maximum ATP yield per glucose molecule during aerobic respiration?

Accepted Answer

The theoretical maximum is about 30-32 ATP per glucose.

Question 19

A yeast cell is growing in an anaerobic environment. Which of the following products would you expect to find?

Accepted Answer

Ethanol and CO$$_2$$

Question 20

Which of the following best describes the role of ATP synthase in cellular respiration?

Accepted Answer

It synthesizes ATP as protons flow down their gradient from the intermembrane space to the mitochondrial matrix.

Chapter 6: Harvesting Chemical Energy - Study Guide

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