$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 \rightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2O + \text{ATP} + \text{heat}$$

Question 1

Which of the following best describes the main function of cellular respiration in eukaryotic cells?

Accepted Answer

To break down glucose and produce ATP for cellular work

Question 2

Which equation correctly represents the overall process of aerobic cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 ightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2O + 	ext{ATP} + 	ext{heat}$$

Question 3

During glycolysis, what is the net gain of ATP and NADH molecules per molecule of glucose?

Accepted Answer

2 ATP, 2 NADH

Question 4

Which of the following statements about the citric acid cycle (Krebs cycle) is correct?

Accepted Answer

It produces NADH, FADH$$_2$$, ATP, and CO$$_2 as $$products

Question 5

What is the primary role of oxygen in cellular respiration?

Accepted Answer

To accept electrons at the end of the electron transport chain, forming water

Question 6

Which process is responsible for creating the proton (H$$^+) $$gradient used to power ATP synthase?

Accepted Answer

Electron transport chain

Question 7

A muscle cell is rapidly using up oxygen during intense exercise. Which pathway will it rely on for ATP production?

Accepted Answer

Lactic acid fermentation

Question 8

Which of the following is a correct description of a redox reaction in cellular respiration?

Accepted Answer

Oxygen is reduced to water

Question 9

Which of the following organisms is an example of a chemoautotroph?

Accepted Answer

A bacterium oxidizing inorganic compounds in a hot spring

Question 10

What is the main purpose of fermentation in cells?

Accepted Answer

To regenerate NAD$$^+ so $$glycolysis can continue

Question 11

Which molecule acts as an electron carrier during cellular respiration?

Accepted Answer

NADH

Question 12

If a poison blocks the function of ATP synthase, what would be the immediate effect on the cell?

Accepted Answer

ATP production by oxidative phosphorylation would decrease

Question 13

Which of the following best explains why lactic acid fermentation is considered less efficient than aerobic respiration?

Accepted Answer

It produces less ATP per glucose molecule

Question 14

Which step in cellular respiration produces the most ATP?

Accepted Answer

Electron transport chain and chemiosmosis

Question 15

A genetic mutation prevents the reduction of FAD to FADH$$_2 in $$the citric acid cycle. What is the most likely consequence?

Accepted Answer

The electron transport chain will receive fewer electrons, decreasing ATP production

Question 16

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

Accepted Answer

ATP binds to an enzyme early in glycolysis, decreasing its activity

Question 17

Which of the following best describes the fate of pyruvate in the presence of oxygen?

Accepted Answer

It is transported into the mitochondrion and converted to acetyl-CoA

Question 18

In the electron transport chain, what is the direct source of energy used to synthesize ATP?

Accepted Answer

The flow of protons (H$$^+) $$through ATP synthase

Question 19

Which of the following is a product of alcoholic fermentation?

Accepted Answer

Ethanol and CO$$_2$$

Question 20

Which of the following best explains why chemoautotrophs are important in extreme environments like hot springs?

Accepted Answer

They obtain energy by oxidizing inorganic compounds, supporting unique ecosystems

Cellular Respiration: Pathways and Mechanisms

Study Guide - Practice Questions