Question 1

Which of the following statements best describes the main difference between aerobic and anaerobic respiration in prokaryotes?

Accepted Answer

Aerobic respiration uses oxygen as the terminal electron acceptor, while anaerobic respiration uses a different molecule such as nitrate or sulfate.

Question 2

During fermentation, why must NAD$$^+ be $$regenerated?

Accepted Answer

To allow glycolysis to continue by accepting electrons from glucose oxidation.

Question 3

A bacterium is growing in a medium with glucose but no oxygen. It produces ethanol and CO$$_2 as $$end products. Which pathway is it using?

Accepted Answer

Alcoholic fermentation

Question 4

Which of the following equations correctly represents the overall process of photosynthesis?

Accepted Answer

$$6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O} \xrightarrow{	ext{light}} \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{O}_2$$

Question 5

Which of the following best explains why fermentation produces less ATP than aerobic respiration?

Accepted Answer

Fermentation does not use the electron transport chain, so less energy is extracted from glucose.

Question 6

A Durham tube test shows a yellow color and a gas bubble in the tube. What does this indicate about the organism?

Accepted Answer

The organism ferments the sugar and produces both acid and gas.

Question 7

Which of the following is a correct description of the role of exoenzymes in microbial metabolism?

Accepted Answer

Exoenzymes are secreted outside the cell to break down large macromolecules into smaller units that can be transported into the cell.

Question 8

Which of the following best describes the fate of fatty acids during catabolism in bacteria?

Accepted Answer

Fatty acids are degraded by $$\beta-$$oxidation into acetyl-CoA, which enters the Krebs cycle.

Question 9

A culture of E. coli is growing rapidly on a complex carbohydrate in the absence of oxygen. Which of the following processes is most likely occurring?

Accepted Answer

Glycolysis followed by fermentation, with exoenzymes breaking down the carbohydrate into monosaccharides.

Question 10

Which of the following is a correct pairing of nutritional type and example organism?

Accepted Answer

Photoautotroph – Cyanobacteria

Question 11

Which of the following statements about the Calvin cycle is correct?

Accepted Answer

The Calvin cycle uses ATP and NADPH to fix CO$$_2$$ into sugars.

Question 12

Which of the following is the correct order of events in aerobic respiration?

Accepted Answer

Glycolysis $$\rightarrow$$ Krebs cycle $$\rightarrow$$ Electron transport chain

Question 13

Which of the following best explains why the energy yield from glucose is lower in fermentation than in aerobic respiration?

Accepted Answer

Fermentation does not fully oxidize glucose to CO$$_2$$ and H$$_2O$$, so less energy is extracted.

Question 14

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactic acid

Question 15

Which of the following best describes the function of the electron transport chain in cellular respiration?

Accepted Answer

It transfers electrons from NADH and FADH$$_2 to a $$terminal electron acceptor, generating a proton gradient used to produce ATP.

Question 16

Which of the following is a correct statement about amphibolic pathways?

Accepted Answer

They function in both catabolism and anabolism.

Question 17

Which of the following is the correct chemical equation for the oxidation-reduction reactions in photosynthesis?

Accepted Answer

$$6\ \mathrm{CO}_2 + 12\ \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{H}_2\mathrm{O} + 6\ \mathrm{O}_2$$

Question 18

Which of the following best describes the role of nitrate in anaerobic respiration?

Accepted Answer

Nitrate acts as a terminal electron acceptor in the electron transport chain, being reduced to nitrite or other nitrogen compounds.

Microbial Metabolism: Respiration, Fermentation, and Metabolic Diversity

Study Guide - Practice Questions

Study Guide - Flashcards