$$\text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 2\ \text{C}_3\text{H}_6\text{O}_3$$

$$\text{Glucose} + 2\ \text{ADP} + 2\ \text{P}_i \rightarrow 2\ \text{Pyruvate} + 2\ \text{ATP} + 2\ \text{NADH}$$

Question 1

Which of the following best describes the main purpose of fermentation in cells?

Accepted Answer

To regenerate NAD$$ ^+  so $$glycolysis can continue in the absence of oxygen

Question 2

During strenuous exercise, your muscle cells switch to lactic acid fermentation. What is the immediate benefit of this metabolic shift?

Accepted Answer

It enables glycolysis to continue producing ATP when oxygen is scarce

Question 3

Which of the following equations correctly represents the net reaction for lactic acid fermentation?

Accepted Answer

$$	ext{C}_6	ext{H}_{12}	ext{O}_6 ightarrow 2\ 	ext{C}_3	ext{H}_6	ext{O}_3$$

Question 4

Which of the following organisms is most likely to use alcohol fermentation as its primary means of energy extraction in the absence of oxygen?

Accepted Answer

Yeast cells

Question 5

What is the main reason why fermentation is less efficient than aerobic respiration in terms of ATP yield?

Accepted Answer

Fermentation does not fully oxidize glucose to carbon dioxide

Question 6

Which of the following is a correct sequence of events during alcohol fermentation?

Accepted Answer

Glucose → Pyruvate → Ethanol + CO$$_2$$

Question 7

In the absence of oxygen, which molecule acts as the final electron acceptor during lactic acid fermentation?

Accepted Answer

Pyruvate

Question 8

Which of the following best explains why Swiss cheese has holes, even though lactic acid fermentation does not produce CO$$_2$$?

Accepted Answer

Other bacteria in the cheese produce CO$$_2$$ during fermentation

Question 9

Which of the following statements about glycolysis is TRUE for both fermentation and cellular respiration?

Accepted Answer

Glycolysis occurs in the cytoplasm and produces pyruvate, ATP, and NADH

Question 10

A patient with a genetic defect that prevents pyruvate from entering the mitochondria would be able to produce ATP by which process?

Accepted Answer

Glycolysis followed by fermentation

Question 11

Which of the following is a direct output of glycolysis?

Accepted Answer

Pyruvate

Question 12

Which of the following best describes the fate of NADH produced during glycolysis under anaerobic conditions?

Accepted Answer

It is oxidized back to NAD$$^+$$ during fermentation

Question 13

Which of the following is NOT a product of lactic acid fermentation?

Accepted Answer

CO$$_2$$

Question 14

Which of the following equations correctly represents the net ATP yield from glycolysis of one glucose molecule?

Accepted Answer

$$	ext{Glucose} + 2\ 	ext{ADP} + 2\ 	ext{P}_i ightarrow 2\ 	ext{Pyruvate} + 2\ 	ext{ATP} + 2\ 	ext{NADH}$$

Question 15

Which of the following best explains why red blood cells rely exclusively on glycolysis and fermentation for ATP production?

Accepted Answer

They lack mitochondria

Question 16

Which of the following is a key difference between lactic acid fermentation and alcohol fermentation?

Accepted Answer

Alcohol fermentation produces ethanol and CO$$_2$$, while lactic acid fermentation produces only lactic acid

Question 17

Which of the following best describes the role of glycolysis in both fermentation and cellular respiration?

Accepted Answer

It converts glucose to pyruvate, generating ATP and NADH

Question 18

A batch of yogurt is made by adding bacteria to milk. Which metabolic process is primarily responsible for the sour taste of yogurt?

Accepted Answer

Lactic acid fermentation

Question 19

Which of the following is a shared feature of both fermentation and aerobic cellular respiration?

Accepted Answer

Both processes begin with glycolysis

How Cells Harvest Chemical Energy: Fermentation and Cellular Respiration

Study Guide - Practice Questions