Question 1

Which of the following best describes the relationship between catabolism and anabolism in cellular metabolism?

Accepted Answer

Catabolism breaks down large molecules to release energy, and anabolism uses that energy to build larger molecules, forming a continuous cycle.

Question 2

A bacterium that uses inorganic compounds such as $$\mathrm{H_2S}$$ for energy and $$\mathrm{CO_2$} as $$its carbon source is best classified as:

Accepted Answer

Lithoautotroph

Question 3

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

Accepted Answer

2 ATP

Question 4

Which pathway produces NADPH and 5-carbon sugars for biosynthesis, running alongside glycolysis?

Accepted Answer

Pentose Phosphate Pathway (PPP)

Question 5

In the electron transport system (ETS) of aerobic respiration, what is the final electron acceptor?

Accepted Answer

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

Question 6

Which of the following statements about fermentation is TRUE?

Accepted Answer

Fermentation occurs in the cytoplasm and produces lactic acid or ethanol, depending on the organism.

Question 7

A yeast cell is placed in an anaerobic environment. Which products will it most likely produce during glucose metabolism?

Accepted Answer

Ethanol, $$\mathrm{CO_2$}$$, and ATP

Question 8

Which process directly generates the proton motive force (PMF) used for ATP synthesis?

Accepted Answer

Electron transport system pumping $$\mathrm{H^+}$$ across a membrane

Question 9

What is the main purpose of chemiosmosis in cellular respiration?

Accepted Answer

To allow $$\mathrm{H^+}$$ ions to flow through ATP synthase, generating ATP

Question 10

Which of the following best explains why lipids yield more energy per gram than carbohydrates during catabolism?

Accepted Answer

Lipids enter the energy cycle as acetyl-CoA after beta-oxidation, allowing more electrons to be transferred to NADH and FADH2.

Question 11

A patient with a genetic defect preventing deamination of amino acids would most likely experience which of the following?

Accepted Answer

Accumulation of toxic nitrogen compounds in the body

Question 12

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

Accepted Answer

2 Pyruvate

Question 13

Which step in cellular respiration produces the greatest amount of ATP?

Accepted Answer

Electron transport system (ETS)

Question 14

Which of the following statements about anaerobic respiration is correct?

Accepted Answer

Anaerobic respiration uses an electron transport chain but with a final electron acceptor other than oxygen.

Question 15

Which of the following is a major difference between fermentation and anaerobic respiration?

Accepted Answer

Fermentation does not use an electron transport chain, while anaerobic respiration does.

Question 16

Which of the following best describes the fate of the carbon skeletons from amino acids after deamination?

Accepted Answer

They enter the energy cycle as pyruvate, acetyl-CoA, or Krebs cycle intermediates.

Question 17

Which of the following organisms is an example of a photoautotroph?

Accepted Answer

Cyanobacteria

Question 18

During the breakdown of lipids, which process converts fatty acids into acetyl-CoA?

Accepted Answer

Beta-oxidation

Question 19

Which of the following is a product of fermentation in humans?

Accepted Answer

Lactic acid

Question 20

A cell is exposed to a toxin that inhibits ATP synthase. Which process will be directly affected?

Accepted Answer

The flow of $$\mathrm{H^+}$$ ions across the membrane to generate ATP

Microbial Metabolism: Catabolism, Anabolism, and Energy Pathways

Study Guide - Practice Questions