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

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

Question 1

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

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain, forming water.

Question 2

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

Accepted Answer

$$2$$ ATP and $$2$$ NADH

Question 3

Which process occurs in the cytosol of both prokaryotic and eukaryotic cells and does not require oxygen?

Accepted Answer

Glycolysis

Question 4

What is the main purpose of fermentation in cells?

Accepted Answer

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

Question 5

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

Accepted Answer

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

Question 6

Which molecule is reduced during the process of cellular respiration?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 7

In the absence of oxygen, muscle cells can switch to which metabolic pathway to continue producing ATP?

Accepted Answer

Lactic acid fermentation

Question 8

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

Accepted Answer

It completes the oxidation of glucose derivatives, producing NADH, FADH$$_2$$, ATP, and CO$$_2.$$

Question 9

What is the main difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Substrate-level phosphorylation transfers a phosphate group directly from a substrate to ADP, while oxidative phosphorylation uses a proton gradient and ATP synthase.

Question 10

Which of the following best explains why fats yield more ATP per gram than carbohydrates?

Accepted Answer

Fats have more hydrogen atoms, making them more reduced and able to donate more electrons to the electron transport chain.

Question 11

A poison that blocks the function of ATP synthase would directly affect which process?

Accepted Answer

Chemiosmosis

Question 12

Which of the following is a correct sequence of events for the flow of electrons during aerobic cellular respiration?

Accepted Answer

Glucose $$\rightarrow$$ NADH $$\rightarrow$$ Electron Transport Chain $$\rightarrow$$ Oxygen

Question 13

Which of the following is NOT a product of the citric acid cycle?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 14

Which of the following statements about fermentation is TRUE?

Accepted Answer

Fermentation allows glycolysis to continue by regenerating NAD$$^+ in $$the absence of oxygen.

Question 15

If a cell is unable to remove the amino group from amino acids, which metabolic process would be directly affected?

Accepted Answer

Catabolism of proteins for energy

Question 16

Which of the following best describes the fate of pyruvate in the absence of oxygen in yeast cells?

Accepted Answer

It is converted to ethanol and carbon dioxide.

Question 17

Which of the following is a key difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses oxygen as the final electron acceptor, while anaerobic respiration uses other molecules such as sulfur or nitrogen.

Question 18

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

Accepted Answer

Anabolic pathways consume energy to build complex molecules, while catabolic pathways release energy by breaking down complex molecules.

Question 19

A patient is diagnosed with a mitochondrial disorder that impairs the electron transport chain. Which of the following would most likely be observed in this patient’s cells?

Accepted Answer

Decreased ATP production and increased reliance on glycolysis for energy

Question 20

Which of the following best explains why glycolysis is considered one of the most ancient metabolic pathways?

Accepted Answer

It occurs in the cytosol and does not require oxygen, making it possible in early Earth conditions.

Cellular Respiration and Fermentation: Mechanisms and Pathways

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