Q: Which of the following equations correctly represents the net ATP yield from aerobic respiration in a bacterial cell?

$$38 \\ \text{ATP} = 2 \\ \text{(glycolysis)} + 2 \\ \text{(Krebs cycle)} + 34 \\ \text{(ETC)}$$

Question 1

Which of the following best explains why eukaryotic cells produce fewer ATP molecules per glucose molecule than prokaryotic cells during aerobic respiration?

Accepted Answer

Eukaryotic cells lose energy transporting intermediates into the mitochondria, reducing net ATP yield.

Question 2

In bacterial cells, where does the electron transport chain (ETC) occur, and what is the immediate result of its activity?

Accepted Answer

In the cell membrane, pumping protons into the periplasmic space.

Question 3

A bacterium is growing in an environment lacking carbohydrates but rich in lipids. Which metabolic process will it primarily use to generate acetyl-CoA for the Krebs cycle?

Accepted Answer

Beta oxidation of fatty acids

Question 4

Which of the following statements about the Entner-Doudoroff pathway is correct?

Accepted Answer

It produces NADPH, which is used in biosynthetic (anabolic) reactions.

Question 5

During aerobic respiration in eukaryotic cells, protons are pumped into which compartment to create the proton gradient used by ATP synthase?

Accepted Answer

The intermembrane space of the mitochondria

Question 6

A cell is forced to metabolize proteins for energy. Which enzyme types are primarily responsible for breaking down proteins into amino acids?

Accepted Answer

Proteases and peptidases

Question 7

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by transferring a phosphate group from a metabolic intermediate to ADP.

Question 8

Which pathway is primarily responsible for generating ribose for nucleic acid synthesis in both bacteria and humans?

Accepted Answer

Pentose phosphate pathway

Question 9

A mutation disables a bacterium's ability to perform chemiosmosis. Which process will be directly affected?

Accepted Answer

Oxidative phosphorylation

Question 10

Which of the following equations correctly represents the net ATP yield from aerobic respiration in a bacterial cell?

Accepted Answer

$$38 \ 	ext{ATP} = 2 \ 	ext{(glycolysis)} + 2 \ 	ext{(Krebs cycle)} + 34 \ 	ext{(ETC)}$$

Question 11

Which of the following is NOT a possible energy source for chemotrophic cells when carbohydrates are unavailable?

Accepted Answer

Nucleic acids

Question 12

Which type of phosphorylation is unique to autotrophs and is the first step in photosynthesis?

Accepted Answer

Photophosphorylation

Question 13

A patient’s muscle cells are deprived of oxygen. Which metabolic pathway will their cells rely on to generate ATP, and what is a key characteristic of this process?

Accepted Answer

Fermentation; does not require oxygen and is faster but less efficient

Question 14

Which of the following best describes the role of NADPH produced in the Entner-Doudoroff pathway?

Accepted Answer

It provides reducing power for biosynthetic (anabolic) reactions.

Question 15

Which of the following is a correct sequence of events for aerobic respiration in a eukaryotic cell?

Accepted Answer

Glycolysis in cytoplasm → Krebs cycle in inner mitochondrial membrane → ETC in inner mitochondrial membrane

Question 16

A cell is synthesizing fatty acids. Which of the following statements is true about this process?

Accepted Answer

It is an endergonic process that consumes energy.

Question 17

Which of the following best describes chemiosmosis?

Accepted Answer

The movement of protons down their concentration gradient through ATP synthase to generate ATP.

Question 18

Which of the following is a key feature of the endosymbiotic theory as it relates to cellular respiration?

Accepted Answer

Eukaryotic cells evolved mitochondria from engulfed prokaryotes, allowing for more efficient energy production.

Question 19

If a chemotrophic cell is deprived of both carbohydrates and lipids, which macromolecule will it metabolize next for energy, and what is the first step in this process?

Accepted Answer

Proteins; breakdown by proteases and peptidases into amino acids

Question 20

Which of the following best explains why the Entner-Doudoroff pathway is advantageous for some bacteria despite its lower ATP yield?

Accepted Answer

It produces NADPH for biosynthetic reactions and requires fewer enzymes.

Microbial Metabolism: Cellular Respiration and Alternative Pathways

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