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

Question 1

Which of the following best describes substrate-level phosphorylation during cellular respiration?

Accepted Answer

ATP is produced directly by transferring a phosphate group from a substrate to ADP.

Question 2

Which of the following is the correct summary equation for aerobic cellular respiration?

Accepted Answer

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

Question 3

During the electron transport chain (ETC) in mitochondria, what is the final electron acceptor?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 4

Which of the following statements about chemiosmosis is correct?

Accepted Answer

It involves the movement of protons down their concentration gradient through ATP synthase to produce ATP.

Question 5

Which of the following molecules is oxidized during glycolysis?

Accepted Answer

Glucose

Question 6

Where in the mitochondrion does the Krebs (citric acid) cycle occur?

Accepted Answer

Mitochondrial matrix

Question 7

Which of the following best explains why fermentation occurs in muscle cells during intense exercise?

Accepted Answer

Oxygen is not available, so cells regenerate NAD+ by reducing pyruvate to lactate.

Question 8

Which of the following is a correct comparison between fermentation and aerobic cellular respiration?

Accepted Answer

Fermentation produces less ATP per glucose molecule than aerobic respiration.

Question 9

Which of the following is an example of feedback inhibition in cellular respiration?

Accepted Answer

High levels of ATP inhibit phosphofructokinase, slowing glycolysis.

Question 10

Which of the following statements about electron carriers is correct?

Accepted Answer

NADH and FADH2 donate electrons to the electron transport chain, becoming oxidized to NAD+ and FAD.

Question 11

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

Accepted Answer

Oxidative phosphorylation

Question 12

Which of the following best describes the fate of the carbons from glucose during aerobic cellular respiration?

Accepted Answer

They are released as carbon dioxide ($$\mathrm{CO_2$}) $$during the Krebs cycle and pyruvate oxidation.

Question 13

Which of the following is NOT a product of the electron transport chain?

Accepted Answer

NADH

Question 14

Which of the following best explains why fats yield more ATP per gram than carbohydrates when used as an energy source?

Accepted Answer

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

Question 15

Which compartment of the mitochondrion accumulates protons during electron transport, creating the proton gradient used for ATP synthesis?

Accepted Answer

Intermembrane space

Question 16

Which of the following is a metabolic intermediate in the conversion of glucose to carbon dioxide?

Accepted Answer

Pyruvate

Question 17

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

Accepted Answer

It synthesizes ATP as protons flow through it down their electrochemical gradient.

Question 18

Which of the following statements about the use of proteins as an energy source is correct?

Accepted Answer

Proteins are broken down into amino acids, which can enter the Krebs cycle after deamination.

Question 19

If a cell is exposed to cyanide, which blocks the transfer of electrons to oxygen in the electron transport chain, what is the most immediate effect?

Accepted Answer

ATP production by oxidative phosphorylation stops.

Question 20

Which of the following best explains how organic molecules from food can be used to build cellular structures?

Accepted Answer

Intermediates from cellular respiration can be diverted to biosynthetic pathways to form amino acids, nucleotides, and lipids.

Chapter 6: Harvesting Chemical Energy – Study Guide and Key Concepts

Study Guide - Practice Questions