Question 1

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

Accepted Answer

Catabolic reactions release energy that is used to power anabolic reactions.

Question 2

A scientist is studying an enzyme-catalyzed reaction. She increases the substrate concentration, but the reaction rate does not increase further. What is the most likely explanation?

Accepted Answer

The enzyme's active sites are saturated with substrate.

Question 3

Which of the following statements about competitive and noncompetitive enzyme inhibitors is correct?

Accepted Answer

Competitive inhibitors can be overcome by increasing substrate concentration, while noncompetitive inhibitors usually cannot.

Question 4

During aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 5

Which process is responsible for regenerating NAD$$^+ so $$glycolysis can continue in the absence of an electron transport chain?

Accepted Answer

Fermentation

Question 6

A bacterium is placed in an environment lacking oxygen but containing nitrate ($$\mathrm{NO_3$^-}). $$Which type of respiration will it most likely perform?

Accepted Answer

Anaerobic respiration

Question 7

Which of the following best explains why enzymes are considered biological catalysts?

Accepted Answer

They lower the activation energy and are not consumed in the reaction.

Question 8

Which equation correctly represents the reduction of NAD$$^+$$ during glycolysis?

Accepted Answer

$$\mathrm{NAD^+ + 2H^+ + 2e^- \rightarrow NADH + H^+}$$

Question 9

Which pathway is amphibolic, participating in both catabolic and anabolic reactions?

Accepted Answer

Krebs cycle

Question 10

A cell is exposed to a noncompetitive inhibitor. Which of the following is most likely to occur?

Accepted Answer

The inhibitor binds to an allosteric site, changing the enzyme's shape and function.

Question 11

Which of the following is NOT a product of glycolysis?

Accepted Answer

CO$$_2$$

Question 12

Which process directly transfers a phosphate group from a substrate to ADP to form ATP?

Accepted Answer

Substrate-level phosphorylation

Question 13

Which nutritional pattern describes an organism that uses light energy and CO$$_2 as $$its carbon source?

Accepted Answer

Photoautotroph

Question 14

A microbe is found to produce lactic acid as a waste product in the absence of oxygen. Which metabolic pathway is it using?

Accepted Answer

Lactic acid fermentation

Question 15

Which of the following best describes the role of oxygen in the electron transport chain?

Accepted Answer

It acts as the terminal electron acceptor, forming water.

Question 16

Which equation represents the overall reaction for aerobic glucose catabolism?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP}$$

Question 17

Which of the following is a key difference between respiration and fermentation?

Accepted Answer

Respiration uses an electron transport chain, while fermentation does not.

Question 18

Which pathway provides NADPH and five-carbon sugars for biosynthesis of nucleic acids?

Accepted Answer

Pentose phosphate pathway

Question 19

A cell is exposed to extreme pH. What is the most likely effect on its enzymes?

Accepted Answer

Enzymes will be denatured, losing their function.

Question 20

Which of the following is true about feedback inhibition in metabolic pathways?

Accepted Answer

The pathway end product inhibits an early step, preventing overproduction.

Microbial Metabolism: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards