Question 1

Which of the following best describes the role of a noncompetitive (allosteric) inhibitor in enzyme regulation?

Accepted Answer

It binds to a site other than the active site, causing a conformational change that reduces enzyme activity.

Question 2

A bacterial cell is placed in a hypertonic solution. What is the most likely outcome for the cell?

Accepted Answer

Water will leave the cell, causing it to shrink.

Question 3

During glycolysis, what is the net gain of ATP and NADH per molecule of glucose?

Accepted Answer

$$2$$ ATP and $$2$$ NADH

Question 4

Which of the following best explains why enzymes lower the activation energy of a chemical reaction?

Accepted Answer

They provide a surface for substrates to react more easily.

Question 5

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

Accepted Answer

Nonsense mutation

Question 6

Which of the following best describes the function of restriction enzymes in biotechnology?

Accepted Answer

They cut DNA at specific nucleotide sequences.

Question 7

A facultative anaerobe is placed in an environment with no oxygen. What will most likely happen?

Accepted Answer

It will switch to anaerobic metabolism and continue to grow.

Question 8

Which process is responsible for the transfer of genetic material from one bacterium to another via a virus?

Accepted Answer

Transduction

Question 9

In the lac operon, what happens when lactose is present in the environment?

Accepted Answer

The operon is induced and enzymes for lactose metabolism are produced.

Question 10

Which of the following best describes the Calvin Cycle?

Accepted Answer

It uses ATP and NADPH to fix $$CO_2$$ into glucose.

Question 11

A scientist wants to separate DNA fragments by size. Which technique should they use?

Accepted Answer

Gel electrophoresis

Question 12

Which of the following is an example of a saprobe?

Accepted Answer

A fungus that decomposes dead organic matter.

Question 13

What is the main function of coenzymes in enzymatic reactions?

Accepted Answer

They are organic cofactors that assist enzyme function, often derived from vitamins.

Question 14

Which phase of the bacterial growth curve is characterized by rapid cell division and exponential increase in population?

Accepted Answer

Log (exponential) phase

Question 15

A mutation causes the insertion of a single nucleotide into a gene. What is the most likely result?

Accepted Answer

Frameshift mutation

Question 16

Which of the following best describes the function of ATP synthase?

Accepted Answer

It synthesizes ATP using a proton gradient across a membrane.

Question 17

Which of the following is a correct pairing of nutritional type and energy source?

Accepted Answer

Chemoautotroph – chemicals

Question 18

A researcher is studying a bacterium that thrives in high salt concentrations. What is the correct term for this organism?

Accepted Answer

Halophile

Question 19

Which of the following statements about DNA replication in prokaryotes is correct?

Accepted Answer

DNA polymerase adds nucleotides in the 5' to 3' direction.

Question 20

Which of the following best describes the process of transcription?

Accepted Answer

DNA is copied into mRNA.

Microbiology Study Guide: Metabolism, Enzymes, Nutrition, Genetics, and Biotechnology

Study Guide - Practice Questions