Question 1

Which of the following best describes the main function of the Krebs cycle in cellular respiration?

Accepted Answer

To transfer energy to electron carriers NADH and FADH$$_2$$

Question 2

Where does the electron transport chain occur in eukaryotic cells?

Accepted Answer

In the inner mitochondrial membrane (cristae)

Question 3

During aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen (O$$_2)$$

Question 4

Which equation correctly represents the net ATP yield from fermentation per glucose molecule?

Accepted Answer

$$	ext{Net ATP} = 2$$

Question 5

What is the primary purpose of fermentation in cells?

Accepted Answer

To regenerate NAD$$^+$$ for glycolysis

Question 6

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

Accepted Answer

Lactate

Question 7

Alcoholic fermentation converts pyruvate into which compound?

Accepted Answer

Ethanol

Question 8

Which process occurs in the cytoplasm and does not require oxygen?

Accepted Answer

Fermentation

Question 9

What is the total net ATP yield from aerobic cellular respiration per glucose molecule?

Accepted Answer

$$	ext{Net ATP} = 38$$

Question 10

Which of the following statements about the Krebs cycle is TRUE?

Accepted Answer

It produces NADH and FADH$$_2 as $$electron carriers

Question 11

During the electron transport chain, what drives the synthesis of ATP?

Accepted Answer

Proton gradient across the mitochondrial membrane

Question 12

Which of the following is a waste product of the Krebs cycle?

Accepted Answer

Carbon dioxide (CO$$_2)$$

Question 13

Which process is responsible for transferring electrons from NADH and FADH$$_2 to $$oxygen?

Accepted Answer

Electron transport chain

Question 14

Which of the following occurs in muscle cells during intense exercise when oxygen is low?

Accepted Answer

Lactic acid fermentation

Question 15

What is the role of NAD$$^+ in $$glycolysis and fermentation?

Accepted Answer

It is regenerated to allow glycolysis to continue

Question 16

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

Accepted Answer

Fermentation does not use the electron transport chain

Question 17

If a cell is deprived of oxygen, which process will it rely on to generate ATP?

Accepted Answer

Fermentation

Question 18

Which of the following is TRUE about alcoholic fermentation?

Accepted Answer

It occurs in yeast, fungi, and some bacteria

Question 19

Which step in cellular respiration produces the most ATP?

Accepted Answer

Electron transport chain

Question 20

What is the correct sequence of events in aerobic cellular respiration?

Accepted Answer

Glycolysis $$\rightarrow$$ Krebs cycle $$\rightarrow$$ Electron transport chain

Cellular Respiration: Krebs Cycle, Electron Transport Chain, and Fermentation

Study Guide - Practice Questions