Question 1

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

Accepted Answer

Catabolism involves the breakdown of complex molecules to release energy, while anabolism uses energy to build complex molecules from simpler ones.

Question 2

Which of the following is NOT a component of an enzyme?

Accepted Answer

Substrate

Question 3

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 4

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

Accepted Answer

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

Question 5

Which of the following is a product of the Krebs cycle?

Accepted Answer

CO$_2$

Question 6

During oxidative phosphorylation, what is the final electron acceptor in aerobic respiration?

Accepted Answer

O$_2$

Question 7

Which of the following best explains why ATP is considered the 'energy currency' of the cell?

Accepted Answer

ATP stores energy in its high-energy phosphate bonds, which can be hydrolyzed to release energy for cellular processes.

Question 8

Which of the following statements about fermentation is TRUE?

Accepted Answer

Fermentation regenerates NAD$^+$ from NADH, allowing glycolysis to continue in the absence of oxygen.

Question 9

A bacterium is found to use nitrate (NO$_3^-$) as a terminal electron acceptor in the absence of oxygen. This process is best described as:

Accepted Answer

Anaerobic respiration

Question 10

Which of the following best describes an amphibolic pathway?

Accepted Answer

A pathway that can function in both catabolism and anabolism.

Question 11

Which of the following is a key difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Substrate-level phosphorylation directly transfers a phosphate group to ADP, while oxidative phosphorylation uses a proton gradient and ATP synthase.

Question 12

A patient’s bacterial infection is tested using a biochemical assay that detects the presence of catalase. The test is positive. What does this indicate about the bacterium?

Accepted Answer

The bacterium can break down hydrogen peroxide ($2H_2O_2 \rightarrow 2H_2O + O_2$) and is likely aerobic or facultative.

Question 13

Which of the following is a common misconception about noncompetitive enzyme inhibitors?

Accepted Answer

They bind to the active site of the enzyme.

Question 14

Which of the following best describes the role of feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an earlier enzyme, preventing overproduction.

Question 15

Which of the following is the correct sequence of events in aerobic respiration?

Accepted Answer

Glycolysis $\rightarrow$ Krebs cycle $\rightarrow$ Electron transport chain

Question 16

Which of the following statements about the electron transport chain (ETC) is TRUE?

Accepted Answer

The ETC creates a proton gradient across a membrane, which drives ATP synthesis via ATP synthase.

Question 17

Which of the following is a difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses O$_2$ as the final electron acceptor, while anaerobic respiration uses other inorganic molecules.

Question 18

A bacterial culture is grown in the absence of oxygen and produces ethanol and CO$_2$. Which metabolic process is most likely occurring?

Accepted Answer

Alcoholic fermentation

Question 19

Which of the following best explains why glycolysis can occur in both aerobic and anaerobic conditions?

Accepted Answer

Glycolysis does not require oxygen and can regenerate NAD$^+$ through fermentation or the electron transport chain.

Question 20

Which of the following is a correct comparison between photophosphorylation and oxidative phosphorylation?

Accepted Answer

Both processes use an electron transport chain to create a proton gradient that drives ATP synthesis.

Microbial Metabolism: Key Concepts and Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards