$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + \text{Heat and ATP}$$

Question 1

Which of the following best describes the overall chemical equation for cellular respiration in eukaryotic cells?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} ightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 	ext{Heat and ATP}$$

Question 2

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

Accepted Answer

2 ATP and 2 NADH

Question 3

Which enzyme catalyzes the key regulatory step in glycolysis, converting fructose-6-phosphate to fructose-1,6-bisphosphate?

Accepted Answer

Phosphofructokinase

Question 4

Substrate-level phosphorylation refers to:

Accepted Answer

The direct transfer of a phosphate group from a phosphorylated substrate to ADP, forming ATP

Question 5

In the citric acid cycle, how many molecules of CO$$_2$$ are released for each acetyl CoA that enters the cycle?

Accepted Answer

2

Question 6

Which molecule acts as the final electron acceptor in the electron transport chain during aerobic respiration?

Accepted Answer

O$$_2$$

Question 7

If a cell is deprived of oxygen, which process will continue to produce ATP?

Accepted Answer

Glycolysis coupled with fermentation

Question 8

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

Accepted Answer

Fermentation produces less ATP per glucose molecule because it does not fully oxidize glucose to CO$$_2$$

Question 9

During the energy-payoff phase of glycolysis, which molecules are produced?

Accepted Answer

ATP and NADH

Question 10

Which of the following is a real-world application of the citric acid cycle in human metabolism?

Accepted Answer

The citric acid cycle provides intermediates for the synthesis of amino acids and fatty acids

Question 11

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

Accepted Answer

Oxidative phosphorylation

Question 12

A marathon runner relies on cellular respiration for energy. Which stage of cellular respiration provides the most ATP for sustained activity?

Accepted Answer

Electron transport chain and oxidative phosphorylation

Question 13

Which of the following statements about NAD$$^+ is $$correct?

Accepted Answer

NAD$$^+$$ acts as an electron carrier, accepting electrons during glycolysis and the citric acid cycle

Question 14

Which step in glycolysis is considered the committed step, and why?

Accepted Answer

The conversion of fructose-6-phosphate to fructose-1,6-bisphosphate by phosphofructokinase, because it commits glucose to glycolysis

Question 15

Which of the following best describes the role of oxygen in cellular respiration?

Accepted Answer

Oxygen serves as the final electron acceptor in the electron transport chain, allowing for the production of water

Question 16

A patient with a genetic defect in the enzyme pyruvate dehydrogenase would have trouble with which metabolic process?

Accepted Answer

Converting pyruvate to acetyl CoA for entry into the citric acid cycle

Question 17

Which of the following is true about the energy released from glucose during cellular respiration?

Accepted Answer

Most of the energy is captured in ATP, but some is lost as heat

Question 18

Which process allows muscle cells to continue producing ATP during intense exercise when oxygen is limited?

Accepted Answer

Lactic acid fermentation

Question 19

Which of the following is a product of fermentation in yeast cells?

Accepted Answer

Ethanol and CO$$_2$$

Question 20

Which statement best explains why glycolysis is considered an ancient metabolic pathway?

Accepted Answer

Glycolysis occurs in nearly all organisms and does not require oxygen or membrane-bound organelles

Cellular Respiration and Fermentation: The Role of Glucose in Energy Processing

Study Guide - Practice Questions