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

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

Question 1

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

Accepted Answer

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

Question 2

During glycolysis, which of the following is the net gain of ATP and NADH per molecule of glucose?

Accepted Answer

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

Question 3

A patient is diagnosed with a mitochondrial disorder that impairs the function of ATP synthase. Which process would be most directly affected?

Accepted Answer

Chemiosmosis

Question 4

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

Accepted Answer

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

Question 5

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

Accepted Answer

It occurs in the cytoplasm and does not require oxygen, making it suitable for early prokaryotes.

Question 6

In the electron transport chain (ETC), what is the primary function of the protein complexes embedded in the inner mitochondrial membrane?

Accepted Answer

To pump protons ($$\mathrm{H^+}) $$from the mitochondrial matrix to the intermembrane space, creating a proton gradient.

Question 7

A muscle cell is deprived of oxygen during intense exercise. Which process allows it to continue producing ATP, and what is the main byproduct?

Accepted Answer

Lactic acid fermentation; lactic acid

Question 8

Which of the following is a correct sequence of events for the complete aerobic breakdown of one molecule of glucose?

Accepted Answer

Glycolysis $$\rightarrow$$ Pyruvate oxidation $$\rightarrow$$ Krebs cycle $$\rightarrow$$ Oxidative phosphorylation

Question 9

Which of the following statements about redox reactions in cellular respiration is correct?

Accepted Answer

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

Question 10

A person is on a high-protein, low-carbohydrate diet. Which pathway allows amino acids to be used for ATP production in cellular respiration?

Accepted Answer

Amino acids are deaminated and their carbon skeletons enter the Krebs cycle.

Question 11

Which of the following best explains why the electron transport chain (ETC) and chemiosmosis are coupled processes?

Accepted Answer

The ETC creates a proton gradient that drives ATP synthesis via chemiosmosis.

Question 12

Which of the following is a key difference between alcoholic fermentation and lactic acid fermentation?

Accepted Answer

Alcoholic fermentation produces ethanol and carbon dioxide, while lactic acid fermentation produces lactic acid only.

Question 13

If a cell's mitochondria are damaged and unable to function, which process will still occur to produce ATP?

Accepted Answer

Glycolysis

Question 14

Which of the following best describes the fate of NADH produced during glycolysis under anaerobic conditions in human cells?

Accepted Answer

NADH donates electrons to pyruvate, regenerating NAD$$^+$$ and forming lactic acid.

Question 15

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

Accepted Answer

ATP is formed directly by transferring a phosphate group from a substrate to ADP.

Question 16

A genetic mutation causes a defect in the enzyme that converts pyruvate to acetyl-CoA. Which process would be directly impaired?

Accepted Answer

Pyruvate oxidation

Question 17

Which of the following best explains why fats yield more ATP per gram than carbohydrates when used as fuel in cellular respiration?

Accepted Answer

Fats have more reduced carbon atoms, providing more electrons for the electron transport chain.

Question 18

Which of the following is the main reason why fermentation is less efficient than aerobic respiration?

Accepted Answer

Fermentation does not use the electron transport chain, so much less ATP is produced per glucose molecule.

Question 19

A person is fasting and their body begins to break down stored triglycerides for energy. Which pathway do the fatty acids enter to be used for ATP production?

Accepted Answer

Fatty acids are converted to acetyl-CoA and enter the Krebs cycle.

Question 20

Which of the following best describes the chemiosmotic mechanism for ATP synthesis?

Accepted Answer

ATP synthase uses the energy of a proton gradient to convert ADP and inorganic phosphate into ATP.

Cellular Respiration and Redox Reactions: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard