Q: Which of the following equations correctly represents the overall process of aerobic cellular respiration?

$$\text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2 \rightarrow 6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{energy (ATP)}$$

Question 1

Which of the following best describes the main difference between cellular respiration and fermentation in terms of energy yield?

Accepted Answer

Cellular respiration fully oxidizes glucose to CO$$_2$$, producing more ATP, while fermentation only partially oxidizes glucose and yields less ATP.

Question 2

During glycolysis, which enzyme is responsible for the phosphorylation of glucose in the first step, and what is the significance of this reaction?

Accepted Answer

Hexokinase; it traps glucose inside the cell by converting it to glucose-6-phosphate.

Question 3

Which of the following equations correctly represents the overall process of aerobic cellular respiration?

Accepted Answer

$$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2 ightarrow 6 	ext{CO}_2 + 6 	ext{H}_2	ext{O} + 	ext{energy (ATP)}$$

Question 4

A patient’s cells are unable to convert pyruvate to acetyl CoA. Which metabolic process would be directly impaired as a result?

Accepted Answer

Citric acid cycle

Question 5

Which of the following best explains why ATP is considered the 'energy currency' of the cell?

Accepted Answer

ATP stores energy in its phosphate bonds, which can be hydrolyzed to release energy for cellular work.

Question 6

Which of the following statements about the regulation of glycolysis is correct?

Accepted Answer

High levels of ATP inhibit phosphofructokinase by binding to its regulatory site.

Question 7

In the context of cancer metabolism, why might inhibiting an enzyme that allows alanine to be used as an energy source slow the growth of liver cancer cells?

Accepted Answer

It blocks an alternative pathway for ATP production, reducing the energy available for rapid cell division.

Question 8

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by the transfer of a phosphate group from a phosphorylated substrate to ADP.

Question 9

Which of the following macromolecules is used first by cells for ATP production under normal conditions?

Accepted Answer

Carbohydrates

Question 10

A mutation causes pyruvate dehydrogenase to be permanently phosphorylated and inactive. What would be the most immediate effect on cellular respiration?

Accepted Answer

Pyruvate would accumulate and acetyl CoA production would decrease.

Question 11

Which of the following best describes the fate of the carbon atoms from glucose during aerobic cellular respiration?

Accepted Answer

They are released as CO$$_2$$ during pyruvate processing and the citric acid cycle.

Question 12

Which process occurs in the cytosol of eukaryotic cells?

Accepted Answer

Glycolysis

Question 13

Which of the following is NOT a product of glycolysis per molecule of glucose?

Accepted Answer

2 CO$$_2$$

Question 14

Which of the following statements about anabolic and catabolic pathways is correct?

Accepted Answer

Catabolic pathways harvest stored chemical energy to produce ATP.

Question 15

Which of the following best explains why cells must constantly produce ATP?

Accepted Answer

ATP is unstable and cells only store enough for a few seconds to minutes of activity.

Question 16

Which of the following is a direct result of feedback inhibition of phosphofructokinase by ATP?

Accepted Answer

Glycolysis slows down when ATP is abundant.

Question 17

Which of the following statements about the fate of fats in cellular respiration is correct?

Accepted Answer

Fatty acids are converted to acetyl CoA and enter the citric acid cycle.

Question 18

Which of the following is a correct statement about the regulation of pyruvate dehydrogenase?

Accepted Answer

It is inactivated by phosphorylation when ATP, NADH, or acetyl CoA levels are high.

Question 19

Which of the following best describes the role of glycolysis intermediates in anabolic pathways?

Accepted Answer

They can be used to synthesize nucleotides for DNA and RNA.

Cellular Respiration and Fermentation: Pathways of Energy Harvest in Cells

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