Question 1

Which statement best describes the role of competitive enzyme inhibitors?

Accepted Answer

They bind to the active site, directly competing with the substrate for binding.

Question 2

During aerobic respiration in prokaryotes, what is the final electron acceptor in the electron transport chain (ETC)?

Accepted Answer

Oxygen ($O_2$)

Question 3

Which process generates ATP using light energy in photosynthetic organisms?

Accepted Answer

Photophosphorylation

Question 4

A bacterial culture is exposed to UV radiation, resulting in thymine dimers. What type of mutation is most likely to occur?

Accepted Answer

DNA breakage and distortion leading to replication errors

Question 5

Which phase of microbial growth is penicillin most effective against, and why?

Accepted Answer

Log (exponential) phase, because cells are actively dividing and synthesizing cell walls.

Question 6

Which of the following statements about fermentation is TRUE?

Accepted Answer

Fermentation uses organic molecules as final electron acceptors.

Question 7

A bacterium is classified as a halophile. Which environmental condition does it tolerate best?

Accepted Answer

High osmotic pressure due to elevated salt concentrations

Question 8

Which pathway is an alternative to glycolysis and produces NADPH and ATP?

Accepted Answer

Entner-Doudoroff pathway

Question 9

In the lac operon, what happens when lactose is present and glucose is absent?

Accepted Answer

The operon is induced, leading to transcription of genes for lactose metabolism.

Question 10

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP is generated directly from the transfer of a phosphate group from a substrate to ADP.

Question 11

A mutation changes a codon from UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 12

Which media type would you use to selectively grow Staphylococcus aureus and differentiate it from other bacteria?

Accepted Answer

Mannitol Salt Agar

Question 13

Which process describes the uptake of naked DNA by a bacterial cell?

Accepted Answer

Transformation

Question 14

Which statement about DNA replication is correct?

Accepted Answer

DNA replication is semiconservative, with each new molecule containing one old and one new strand.

Question 15

Which environmental condition is optimal for most bacterial growth?

Accepted Answer

pH around 7

Question 16

Which biosafety level is appropriate for teaching labs working with non-pathogenic organisms?

Accepted Answer

BSL-1

Question 17

Which of the following is TRUE about oxidative phosphorylation?

Accepted Answer

It uses the electron transport chain and chemiosmosis to generate ATP.

Question 18

A patient develops a catheter-associated infection with Pseudomonas aeruginosa. Which trait makes this pathogen particularly dangerous in hospital settings?

Accepted Answer

It forms biofilms and is resistant to many antibiotics.

Question 19

Which statement about catabolic and anabolic pathways is correct?

Accepted Answer

Catabolic pathways release energy by breaking down molecules; anabolic pathways require ATP to build molecules.

Question 20

In cyanobacteria, which process is responsible for oxygen production during photosynthesis?

Accepted Answer

Noncyclic photophosphorylation

Microbiology Test 2 Study Guide: Metabolism, Genetics, and Microbial Growth

Study Guide - Practice Questions

Study Guide - Flashcards