$$\mathrm{ADP} + \mathrm{P_{substrate}} \xrightarrow{\text{enzyme}} \mathrm{ATP} + \text{substrate}$$

Question 1

Which of the following best describes the difference between catabolism and anabolism in microbial metabolism?

Accepted Answer

Catabolism breaks down large molecules into smaller ones, releasing energy, while anabolism assembles small molecules into larger ones, using energy.

Question 2

A chemolithoautotroph uses which of the following as its energy and carbon sources?

Accepted Answer

Chemical energy and inorganic CO$$_2 as $$carbon source

Question 3

Which molecule acts as an electron carrier and is reduced during glycolysis?

Accepted Answer

NAD$$^+$$

Question 4

During substrate-level phosphorylation, how is ATP generated?

Accepted Answer

By transferring a high-energy phosphate group directly from a substrate to ADP

Question 5

Which of the following is the final electron acceptor in aerobic respiration?

Accepted Answer

O$$_2$$

Question 6

What is the net ATP yield from glycolysis per molecule of glucose?

Accepted Answer

$$2$$

Question 7

Which process uses light energy to generate ATP via electron transport?

Accepted Answer

Photophosphorylation

Question 8

In the electron transport chain, what is the main consequence of transferring electrons from NADH and FADH$$_2 to O$_2$$?

Accepted Answer

Generation of a proton motive force across the membrane

Question 9

Which of the following statements about glycolysis is correct?

Accepted Answer

Glycolysis produces pyruvate, ATP, and NADH.

Question 10

What is the role of the enzyme in lowering activation energy in a chemical reaction?

Accepted Answer

It provides an alternative reaction pathway with lower activation energy.

Question 11

Which of the following is true about competitive inhibition?

Accepted Answer

The inhibitor blocks substrate binding at the active site.

Question 12

During the Krebs cycle, how many CO$$_2$$ molecules are released per turn?

Accepted Answer

$$2$$

Question 13

Which of the following is NOT a product of the Krebs cycle?

Accepted Answer

Pyruvate

Question 14

What is the main function of NAD$$^+ in $$cellular metabolism?

Accepted Answer

To carry electrons from one reaction to another

Question 15

Which of the following statements about electron carriers is correct?

Accepted Answer

NADH and FADH$$_2$$ are reduced forms that donate electrons to the electron transport chain.

Question 16

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

Accepted Answer

$$\mathrm{ADP} + \mathrm{P_{substrate}} \xrightarrow{	ext{enzyme}} \mathrm{ATP} + 	ext{substrate}$$

Question 17

Which of the following best describes the energy investment phase of glycolysis?

Accepted Answer

ATP is used to modify glucose, preparing it for subsequent breakdown.

Question 18

What is the main difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses oxygen as the final electron acceptor, while anaerobic respiration uses an inorganic molecule other than oxygen.

Question 19

Which of the following is a product of pyruvate decarboxylation before entering the Krebs cycle?

Accepted Answer

Acetyl-CoA

Question 20

In the context of enzyme activity, what happens when the substrate concentration is very high?

Accepted Answer

Enzyme activity reaches a saturation point where no additional substrate can be bound.

Microbial Metabolism and Bioenergetics: Study Notes

Study Guide - Practice Questions