Question 1

Which of the following best describes the main structural difference between Gram-positive and Gram-negative bacterial cell walls?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer reinforced by teichoic acids, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharide.

Question 2

Which component of the Gram-negative bacterial cell wall is responsible for the toxic effects seen in septic shock?

Accepted Answer

Lipopolysaccharide (LPS)

Question 3

A patient is infected with Mycobacterium tuberculosis. Which cell wall feature makes this bacterium resistant to standard Gram staining?

Accepted Answer

Complex cell wall containing mycolic acid

Question 4

Which metabolic pathway is primarily responsible for the production of NADPH and ribose-5-phosphate in bacteria?

Accepted Answer

Pentose phosphate pathway

Question 5

During aerobic respiration, which molecule acts as the final electron acceptor in the electron transport system (ETS)?

Accepted Answer

O$$_2$$

Question 6

Which of the following best describes a lithotroph?

Accepted Answer

An organism that uses inorganic molecules as electron donors for energy generation.

Question 7

Which process is responsible for the breakdown of glucose into two pyruvate molecules, generating ATP and NADH?

Accepted Answer

Glycolysis

Question 8

A mutation occurs in the promoter region of a bacterial operon. What is the most likely effect?

Accepted Answer

Transcription of the operon may be reduced or abolished, affecting protein production.

Question 9

Which enzyme is responsible for synthesizing new DNA strands during replication?

Accepted Answer

DNA polymerase

Question 10

Which of the following is a correct pairing rule for DNA base pairing?

Accepted Answer

A pairs with T, C pairs with G

Question 11

Which of the following is NOT a function of a bacterial capsule?

Accepted Answer

Production of ATP

Question 12

Which of the following statements about mutations is TRUE?

Accepted Answer

Mutations are random changes in the nucleotide sequence of a gene.

Question 13

Which of the following is a product of the TCA cycle that is used in the electron transport chain?

Accepted Answer

NADH

Question 14

Which process involves the conversion of mRNA into a protein?

Accepted Answer

Translation

Question 15

Which of the following is a unique feature of phototrophs?

Accepted Answer

Use of light energy to drive electron transfer

Question 16

A bacterium is found to use ammonia (NH$$_4^+) as $$its electron donor and nitrate (NO$$_3^-) as $$its electron acceptor. Which class of metabolism does this represent?

Accepted Answer

Lithotrophy

Question 17

Which of the following best describes the role of reverse transcriptase in retroviruses?

Accepted Answer

It copies RNA molecules into DNA.

Question 18

Which of the following is a multi-step process that includes initiation, elongation, and termination?

Accepted Answer

Transcription

Question 19

Which of the following mutations is most likely to result in a nonfunctional protein due to a premature stop codon?

Accepted Answer

Nonsense mutation

Question 20

A bacterium is able to survive in environments with very low oxygen concentrations and can use alternative electron acceptors for respiration. Which metabolic strategy does this describe?

Accepted Answer

Anaerobic respiration

Microbial Cell Structure, Metabolism, and Genetics: Study Notes

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