Question 1

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

Accepted Answer

ATP serves as the main energy currency, coupling energy-releasing reactions to energy-consuming processes.

Question 2

During aerobic respiration, which molecule acts as the terminal electron acceptor?

Accepted Answer

O$$_2$$

Question 3

Which process directly generates ATP via substrate-level phosphorylation?

Accepted Answer

Glycolysis

Question 4

A chemoorganotroph obtains energy by:

Accepted Answer

Oxidizing organic compounds

Question 5

In the electron transport chain, the movement of electrons from NADH to O$$_2 is $$coupled to:

Accepted Answer

The generation of a proton motive force across the membrane

Question 6

Which equation correctly represents the net reaction of 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 7

Which of the following statements about fermentation is correct?

Accepted Answer

Fermentation uses organic compounds as both electron donors and acceptors, producing ATP by substrate-level phosphorylation.

Question 8

Which metabolic pathway is essential for the complete oxidation of glucose to CO$$_2 in $$aerobic organisms?

Accepted Answer

Citric acid cycle (CAC)

Question 9

In phototrophic bacteria, what is the primary function of the reaction center?

Accepted Answer

To transfer electrons from light-excited chlorophyll to electron acceptors

Question 10

Which of the following best explains why the reduction potential of PSII chlorophyll is so tightly controlled?

Accepted Answer

To ensure efficient electron transfer and prevent unwanted side reactions

Question 11

Methanogens are unique among microorganisms because they:

Accepted Answer

Produce methane ($$\mathrm{CH_4$}) as a $$metabolic end product

Question 12

Which process is responsible for the assimilation of CO$$_2 in $$the Calvin cycle?

Accepted Answer

RuBisCO catalyzes the carboxylation of ribulose bisphosphate

Question 13

Which of the following is a correct description of an electron donor in microbial metabolism?

Accepted Answer

A molecule that donates electrons to an electron acceptor, becoming oxidized in the process

Question 14

A facultative anaerobe is defined as an organism that:

Accepted Answer

Can grow in both the presence and absence of oxygen

Question 15

Which of the following reactions is an example of denitrification?

Accepted Answer

$$\mathrm{NO_3$^-} \rightarrow \mathrm{NO_2$^-} \rightarrow \mathrm{N_2$}$$

Question 16

Which of the following best describes the function of ATP synthase?

Accepted Answer

It synthesizes ATP using the energy from the proton motive force across the membrane.

Question 17

Which metabolic process is most likely to occur in the absence of external electron acceptors?

Accepted Answer

Fermentation

Question 18

Which of the following is a key difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Oxidative phosphorylation uses electron transport to generate a proton motive force for ATP synthesis.

Question 19

Which of the following best describes the role of RuBisCO in autotrophic metabolism?

Accepted Answer

It catalyzes the carboxylation of ribulose bisphosphate, fixing CO$$_2 in $$the Calvin cycle.

Question 20

A microorganism that uses light as its energy source and CO$$_2 as $$its carbon source is classified as a:

Accepted Answer

Photoautotroph

Fundamentals of Microbial Metabolism and Metabolic Diversity

Study Guide - Practice Questions