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

Question 1

Which of the following best describes the role of NAD+ during cellular respiration?

Accepted Answer

It functions as an oxidizing agent, accepting electrons from food molecules.

Question 2

During glycolysis, glucose ($$C_6H_{12}O_6$) is converted into which molecule before entering the citric acid cycle?

Accepted Answer

Pyruvate

Question 3

What is the net yield of ATP and NADH per glucose molecule during glycolysis?

Accepted Answer

2 ATP and 2 NADH

Question 4

Which enzyme acts as the pacemaker of glycolysis and is regulated by feedback inhibition?

Accepted Answer

Phosphofructokinase

Question 5

In aerobic respiration, what is the overall balanced chemical equation for the breakdown of glucose?

Accepted Answer

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

Question 6

Which process directly produces the majority of ATP during aerobic cellular respiration?

Accepted Answer

Oxidative phosphorylation

Question 7

If oxygen is absent, which molecule must be regenerated to allow glycolysis to continue?

Accepted Answer

NAD+

Question 8

Which of the following statements best explains why fermentation yields much less ATP than aerobic respiration?

Accepted Answer

Fermentation does not utilize the electron transport chain.

Question 9

During the citric acid cycle, which molecule combines with acetyl CoA to form citrate?

Accepted Answer

Oxaloacetate

Question 10

What is the primary function of oxygen in the electron transport chain?

Accepted Answer

To act as the final electron acceptor, forming water ($$H_2O)$$

Question 11

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

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

Question 12

Which location in eukaryotic cells is the site of the electron transport chain?

Accepted Answer

Inner mitochondrial membrane

Question 13

What is the maximum theoretical yield of ATP per glucose molecule during aerobic cellular respiration?

Accepted Answer

32 ATP

Question 14

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactate

Question 15

Which of the following is NOT a stage of aerobic cellular respiration?

Accepted Answer

Fermentation

Question 16

Which of the following best describes the process of oxidation in cellular respiration?

Accepted Answer

Loss of electrons from a substance

Question 17

Which molecule is produced when pyruvate is oxidized before entering the citric acid cycle?

Accepted Answer

Acetyl CoA

Question 18

What is the main regulatory effect of high levels of ATP on phosphofructokinase?

Accepted Answer

It inhibits the enzyme, slowing glycolysis.

Question 19

Which of the following is a real-world consequence of impaired oxidative phosphorylation in human cells?

Accepted Answer

Reduced ATP synthesis, leading to muscle weakness and fatigue

Question 20

In the electron transport chain, what drives the synthesis of ATP by ATP synthase?

Accepted Answer

The proton-motive force (H+ gradient) across the inner mitochondrial membrane

Cellular Respiration: Pathways, Mechanisms, and Regulation

Guida di studio - Domande di pratica