Question 1

Which molecule is the direct product of glycolysis that enters the mitochondria for further energy extraction during aerobic respiration?

Accepted Answer

Pyruvate

Question 2

During the citric acid cycle, what is the fate of the carbons from the original glucose molecule?

Accepted Answer

They are released as CO2

Question 3

Which coenzyme is reduced to FADH2 during the citric acid cycle?

Accepted Answer

FAD

Question 4

What is the primary role of NADH and FADH2 in cellular respiration?

Accepted Answer

To carry high-energy electrons to the electron transport system

Question 5

How many ATP molecules are produced by substrate-level phosphorylation during the citric acid cycle per glucose molecule?

Accepted Answer

2

Question 6

Which process is responsible for the majority of ATP production in cellular respiration?

Accepted Answer

Electron transport system (oxidative phosphorylation)

Question 7

What is the equation for the formation of water at the end of the electron transport system?

Accepted Answer

$$1/2\ \mathrm{O}_2 + 2\mathrm{H}^+ + 2\ e^- \rightarrow \mathrm{H}_2\mathrm{O}$$

Question 8

Which of the following best describes the fate of pyruvate under anaerobic conditions in human muscle cells?

Accepted Answer

It is converted into lactic acid

Question 9

Which macromolecule provides the greatest energy reserve in the human body?

Accepted Answer

Fats

Question 10

What is the net gain of ATP molecules from the complete aerobic catabolism of one glucose molecule, accounting for the cost of shuttling NADH into the mitochondria?

Accepted Answer

36

Question 11

Which step in cellular respiration is responsible for the production of the most water molecules?

Accepted Answer

Electron transport system

Question 12

If a person is fasting and their glycogen stores are depleted, which pathway will the body primarily use to generate ATP?

Accepted Answer

Catabolism of fats

Question 13

Which of the following is a waste product of protein catabolism that is excreted in urine?

Accepted Answer

Urea

Question 14

What is the main reason why fats yield more ATP per gram than carbohydrates?

Accepted Answer

Fats have longer carbon chains, providing more acetyl groups for the citric acid cycle

Question 15

Which enzyme complex is responsible for synthesizing ATP as H+ ions flow back into the mitochondrial matrix?

Accepted Answer

ATP synthase

Question 16

During starvation, why does muscle wasting occur?

Accepted Answer

Proteins are broken down to provide amino acids for energy

Question 17

Which of the following best describes oxidative phosphorylation?

Accepted Answer

ATP production powered by the movement of H+ ions through ATP synthase

Question 18

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

Accepted Answer

6 ATP

Question 19

What is the main function of the carrier proteins in the electron transport system?

Accepted Answer

To transfer electrons and pump H+ ions across the mitochondrial membrane

Question 20

Which of the following equations correctly represents the synthesis of ATP during oxidative phosphorylation?

Accepted Answer

$$\mathrm{ADP} + \mathrm{Pi} \rightarrow \mathrm{ATP}$$

Cellular Respiration: Citric Acid Cycle & Electron Transport System

Study Guide - Practice Questions

Study Guide - Flashcards