Question 1

Which of the following best describes the relationship between catabolic and anabolic reactions in microbial metabolism?

Accepted Answer

Catabolic reactions break down complex molecules to release energy, which is then used by anabolic reactions to build complex molecules from simpler ones.

Question 2

During a redox reaction in microbial metabolism, which of the following statements is correct regarding oxidation and reduction?

Accepted Answer

Oxidation is the loss of hydrogen atoms (and electrons), while reduction is the gain of hydrogen atoms (and electrons).

Question 3

A chemoautotrophic bacterium obtains its energy and carbon from which sources?

Accepted Answer

Inorganic chemicals and carbon dioxide

Question 4

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The active site of an enzyme has a unique three-dimensional shape that only fits specific substrates.

Question 5

Sulfa drugs inhibit bacterial growth by acting as which type of enzyme inhibitor, and how do they function?

Accepted Answer

Competitive inhibitor; they compete with the substrate for the active site of the enzyme.

Question 6

Which environmental factor is LEAST likely to affect the rate of an enzyme-catalyzed reaction in bacteria?

Accepted Answer

Atmospheric pressure

Question 7

What is the main purpose of feedback (end-product) inhibition in a metabolic pathway?

Accepted Answer

To prevent the accumulation of excess end-product by inhibiting an early enzyme in the pathway.

Question 8

During glycolysis, starting with one molecule of glucose, what is the net yield of ATP molecules?

Accepted Answer

$$2$$

Question 9

In the electron transport chain of aerobic respiration, what is the final electron acceptor?

Accepted Answer

Oxygen ($$O_2)$$

Question 10

Where does the electron transport chain occur in prokaryotic cells?

Accepted Answer

On the plasma (cell) membrane

Question 11

Which of the following best describes the process of chemiosmosis in ATP production?

Accepted Answer

ATP is generated as protons flow down their electrochemical gradient through ATP synthase.

Question 12

A bacterium that is killed by exposure to oxygen is classified as a(n):

Accepted Answer

Obligate anaerobe

Question 13

Which of the following statements about bacterial growth temperature preferences is correct?

Accepted Answer

Most bacteria that live in the human body are mesophiles.

Question 14

Halophiles are microorganisms that:

Accepted Answer

Require high concentrations of salt for growth.

Question 15

Why are serial dilutions performed in a microbiology laboratory?

Accepted Answer

To obtain a countable number of colonies by reducing the concentration of bacteria.

Question 16

Which of the following best describes a plasmid in a prokaryotic cell?

Accepted Answer

A small, circular DNA molecule that replicates independently of the chromosome.

Question 17

During DNA replication, which enzyme is responsible for joining Okazaki fragments on the lagging strand?

Accepted Answer

DNA ligase

Question 18

If a DNA sequence is TACTGA, what is the corresponding mRNA sequence produced during transcription?

Accepted Answer

AUGACU

Question 19

Which of the following statements about the lac operon in E. coli is correct when lactose is present?

Accepted Answer

Lactose binds to the repressor, causing it to release from the operator and allowing transcription.

Question 20

Which of the following best distinguishes genotype from phenotype?

Accepted Answer

Genotype is the genetic makeup of an organism, while phenotype is the observable characteristics resulting from gene expression.

Comprehensive Step-by-Step Guidance for Microbiology Exam 2 Study Guide

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