Question 1

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

Accepted Answer

ATP is the main energy carrier, coupling exergonic and endergonic reactions.

Question 2

A bacterium is synthesizing peptidoglycan for its cell wall. Which type of metabolism is primarily involved in this process?

Accepted Answer

Anabolism

Question 3

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

Accepted Answer

The electron donor is oxidized and the electron acceptor is reduced.

Question 4

Given the standard reduction potentials $$E_0$$'$$ for NADH (-0.32$ V) and O_2$ (+0.815$ V), what is the direction of electron flow and what does this imply about energy release?

Accepted Answer

Electrons flow from NADH to $$O_2$$, releasing energy.

Question 5

Which of the following best explains why ATP is considered a 'high-energy' molecule?

Accepted Answer

It contains three phosphate groups that are negatively charged and close together, making the bonds unstable.

Question 6

A reaction has a standard free energy change ($$\Delta G^\circ') of$$ $$-20 kJ/$$mol. What does this indicate about the reaction?

Accepted Answer

The reaction is exergonic and will proceed spontaneously.

Question 7

Which of the following is a correct example of substrate-level phosphorylation?

Accepted Answer

ATP synthesis during glycolysis.

Question 8

Which metabolic class of microorganisms uses inorganic chemicals as an energy source?

Accepted Answer

Chemolithotrophs

Question 9

If a cell is using nitrate ($$NO_3$$^-$$) as a terminal electron acceptor instead of oxygen, which type of respiration is it performing?

Accepted Answer

Anaerobic respiration

Question 10

Which of the following best describes the relationship between $$\Delta G^\circ' ($$standard free energy change) and the equilibrium constant $$K_{eq}$$?

Accepted Answer

$$\Delta G^\circ' = -2.303RT \log K_{eq}$$

Question 11

A microbe is classified as a phototroph. Which of the following statements is true about its metabolism?

Accepted Answer

It obtains energy from light and does not require chemicals as an energy source.

Question 12

Which of the following is NOT a function of central metabolism in microorganisms?

Accepted Answer

Storing genetic information.

Question 13

Which of the following statements about NAD+/NADH is correct?

Accepted Answer

NAD+ is the oxidized form and NADH is the reduced form.

Question 14

Which of the following best describes chemotrophs?

Accepted Answer

They obtain energy from chemical reactions.

Question 15

A cell is performing active transport of ions across its membrane. Which type of cellular work is this?

Accepted Answer

Transport work

Question 16

Which of the following is a correct statement about the laws of thermodynamics as they apply to metabolism?

Accepted Answer

Energy is conserved and can be transformed from one form to another.

Question 17

Which of the following is a real-world example of an exergonic reaction in microbial metabolism?

Accepted Answer

Hydrolysis of ATP to ADP and $$P_i$$

Question 18

Which of the following statements about metabolic pathways is correct?

Accepted Answer

Each step in a metabolic pathway is catalyzed by a specific enzyme or ribozyme.

Question 19

A microbe oxidizes hydrogen sulfide ($$H_2S) to $$sulfate ($$SO_4$$^{2-}$$) for energy. Which metabolic class does it belong to?

Accepted Answer

Chemolithotroph

Question 20

Which of the following is a correct description of the relationship between catabolism and anabolism?

Accepted Answer

Catabolism releases energy, which can be used to drive anabolism.

Microbial Metabolism and Energy Conservation: Study Notes for BIOL 2500

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