Q: Which of the following best represents the overall chemical equation for aerobic cellular respiration?

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

Question 1

Which of the following best represents the overall chemical equation for aerobic cellular respiration?

Accepted Answer

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

Question 2

During glycolysis, what is the net gain of ATP molecules per molecule of glucose?

Accepted Answer

$$2$$ ATP

Question 3

Which enzyme catalyzes the first phosphorylation step in glycolysis, converting glucose to glucose-6-phosphate?

Accepted Answer

Hexokinase

Question 4

What is the primary function of the electron transport chain (ETC) in mitochondria?

Accepted Answer

To create a proton gradient that drives ATP synthesis via chemiosmosis

Question 5

Which molecule acts as the final electron acceptor in the mitochondrial electron transport chain?

Accepted Answer

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

Question 6

In the absence of oxygen, what is the main purpose of fermentation in cells?

Accepted Answer

To regenerate NAD+ so glycolysis can continue

Question 7

Which of the following is NOT a direct product of the citric acid cycle (per glucose, counting both turns)?

Accepted Answer

Pyruvate

Question 8

Which enzyme in the citric acid cycle is unique for also being part of the electron transport chain?

Accepted Answer

Succinate dehydrogenase

Question 9

What is the main metabolic fate of pyruvate under anaerobic conditions in human muscle cells?

Accepted Answer

It is converted to lactate

Question 10

Which process describes the breakdown of fatty acids to produce acetyl-CoA, NADH, and FADH$$_2$$?

Accepted Answer

Beta oxidation

Question 11

A patient with a mitochondrial disorder cannot efficiently use the electron transport chain. Which of the following would most likely accumulate in their cells?

Accepted Answer

NADH

Question 12

Which of the following best explains why oxygen is essential for aerobic respiration?

Accepted Answer

Oxygen acts as the final electron acceptor, allowing the electron transport chain to continue

Question 13

Which of the following statements about substrate-level phosphorylation is correct?

Accepted Answer

It involves the direct transfer of a phosphate group from a substrate to ADP

Question 14

During intense exercise, why do muscle cells switch to lactic acid fermentation?

Accepted Answer

Oxygen supply is insufficient for aerobic respiration

Question 15

Which of the following is a correct description of a redox reaction in cellular respiration?

Accepted Answer

Glucose is oxidized to carbon dioxide, and oxygen is reduced to water

Question 16

What is the main role of NAD+ in cellular respiration?

Accepted Answer

It acts as an electron carrier, accepting electrons during redox reactions

Question 17

Which type of fermentation is characteristic of yeast and produces ethanol and CO$$_2$$?

Accepted Answer

Alcoholic fermentation

Question 18

The Cori cycle describes the recycling loop in which:

Accepted Answer

The liver converts lactate back into glucose, removing it from the blood

Question 19

Which of the following best describes chemiosmosis in mitochondria?

Accepted Answer

H$$^+$$ ions flow back down their gradient through ATP synthase, driving ATP production

Question 20

Which of the following is a product of both glycolysis and the citric acid cycle that feeds electrons into the electron transport chain?

Accepted Answer

NADH

Cellular Respiration and Fermentation: Pathways for Energy Harvest

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