Question 1

Which of the following best describes the role of ATP in microbial metabolism?

Accepted Answer

ATP serves as the main energy currency, coupling catabolic and anabolic reactions.

Question 2

During aerobic respiration of glucose, which molecule acts as the final electron acceptor?

Accepted Answer

O$$_2$$

Question 3

A bacterium that uses light as an energy source, inorganic compounds as electron donors, and CO$$_2 as a $$carbon source is classified as which of the following?

Accepted Answer

Photolithoautotroph

Question 4

Which of the following statements about redox reactions in microbial metabolism is correct?

Accepted Answer

The electron acceptor gains electrons and becomes reduced.

Question 5

In fermentation, ATP is primarily generated by which process?

Accepted Answer

Substrate-level phosphorylation

Question 6

Which of the following best explains why NAD$$^+ is $$important in microbial metabolism?

Accepted Answer

NAD$$^+$$ acts as an electron carrier, cycling between oxidized and reduced forms.

Question 7

A marine bacterium oxidizes thiosulfate (S$$_2O$_3$$^{2-}$$) for energy and requires pyruvate for growth. What is its metabolic classification?

Accepted Answer

Chemolithoheterotroph

Question 8

Which of the following equations correctly represents the overall reaction for aerobic respiration of glucose?

Accepted Answer

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

Question 9

Which process in microbial metabolism directly generates a proton motive force (PMF)?

Accepted Answer

Electron transport chain

Question 10

Which of the following is a key difference between fermentation and respiration in microorganisms?

Accepted Answer

Fermentation uses internal organic molecules as electron acceptors, while respiration uses external electron acceptors.

Question 11

Which of the following best describes the metabolic lifestyle of Thiobacillus denitrificans, which oxidizes ammonia (NH$$_3) $$for energy and fixes CO$$_2$$?

Accepted Answer

Chemolithoautotroph

Question 12

Which of the following statements about anoxygenic phototrophs is correct?

Accepted Answer

They use light for energy but obtain reducing power from organic or inorganic sources.

Question 13

In the context of microbial metabolism, what is meant by 'reducing power'?

Accepted Answer

The ability to donate electrons during electron transfer reactions.

Question 14

Which of the following is a product of fermentation that is commonly used in the food industry?

Accepted Answer

Ethanol

Question 15

During anaerobic respiration in Escherichia coli, which molecule can serve as a terminal electron acceptor instead of oxygen?

Accepted Answer

Nitrate (NO$$_3^-)$$

Question 16

Which of the following best explains why substrate-level phosphorylation is important in fermentation?

Accepted Answer

It allows ATP synthesis without the need for an electron transport chain.

Question 17

Which of the following is a correct statement about the role of electron carriers such as NAD$$^+$$ and NADP$$^+ in $$metabolism?

Accepted Answer

They allow different electron donors and acceptors to interact by shuttling electrons.

Question 18

Which of the following is a key feature of oxidative phosphorylation in microbial cells?

Accepted Answer

ATP synthesis is coupled to the dissipation of a proton motive force across a membrane.

Question 19

Which of the following best describes the metabolic requirements of Roseobacter, which can perform aerobic anoxygenic photosynthesis and requires glucose for growth?

Accepted Answer

Photoorganoheterotroph

Microbial Metabolism: Principles, Pathways, and Diversity

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