Q: Which of the following equations correctly represents the substrate-level phosphorylation of ADP to ATP?

$ADP + P_i + \text{energy} \rightarrow ATP$

Q: Which of the following is a correct summary equation for aerobic respiration of glucose?

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy}$

Question 1

Which of the following best describes the difference between catabolic and anabolic reactions in microbial metabolism?

Accepted Answer

Catabolic reactions break down complex molecules into simpler ones and release energy, while anabolic reactions build complex molecules from simpler ones and require energy input.

Question 2

A scientist is studying a bacterium that can survive in environments lacking oxygen by using nitrate ($NO_3^-$) as a final electron acceptor. Which metabolic process is this bacterium most likely performing?

Accepted Answer

Anaerobic respiration

Question 3

Which of the following statements about enzymes is CORRECT?

Accepted Answer

Enzymes speed up chemical reactions by lowering the activation energy.

Question 4

A competitive inhibitor affects an enzyme by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 5

Which of the following equations correctly represents the substrate-level phosphorylation of ADP to ATP?

Accepted Answer

$ADP + P_i + 	ext{energy} ightarrow ATP$

Question 6

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

Accepted Answer

2

Question 7

Which coenzyme is primarily involved in catabolic redox reactions and acts as an electron carrier?

Accepted Answer

NAD+

Question 8

A mutation in a bacterium prevents it from synthesizing cytochromes. Which metabolic process will be most directly affected?

Accepted Answer

Electron transport chain

Question 9

Which of the following best explains why fermentation produces less ATP than aerobic respiration?

Accepted Answer

Most of the energy in glucose remains in the chemical bonds of the end-products during fermentation.

Question 10

Which of the following is a correct description of an oxidation-reduction (redox) reaction?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 11

In the electron transport chain of prokaryotes, where are the carrier molecules located?

Accepted Answer

Plasma membrane

Question 12

A patient is given a drug that acts as a noncompetitive inhibitor of a bacterial enzyme. What is the most likely effect of this drug on the enzyme?

Accepted Answer

It binds to an allosteric site, changing the enzyme's shape and rendering it nonfunctional.

Question 13

Which of the following is a product of the Krebs cycle for each molecule of glucose?

Accepted Answer

6 NADH

Question 14

Which of the following best describes the role of ATP synthase in chemiosmosis?

Accepted Answer

It synthesizes ATP as protons flow through it down their concentration gradient.

Question 15

Which of the following is a correct summary equation for aerobic respiration of glucose?

Accepted Answer

$C_6H_{12}O_6 + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{energy}$

Question 16

A bacterium is found to lack genes for the electron transport chain. Which metabolic pathway is it most likely to use for energy production in the absence of oxygen?

Accepted Answer

Fermentation

Question 17

Which of the following statements about coenzymes is TRUE?

Accepted Answer

Coenzymes are organic molecules that assist enzymes, often derived from vitamins.

Question 18

Which of the following is a likely consequence if a bacterium is exposed to cyanide, a potent inhibitor of cytochrome c oxidase?

Accepted Answer

The electron transport chain will be blocked, halting ATP production by oxidative phosphorylation.

Question 19

Which of the following best explains why enzymes are essential for life?

Accepted Answer

They allow chemical reactions to occur at rates and temperatures compatible with life.

Question 20

A bacterial cell is placed in an environment with a high concentration of substrate for a particular enzyme. Which of the following is most likely to occur?

Accepted Answer

The enzyme will become saturated, and the reaction rate will reach a maximum.

Microbial Metabolism: Principles and Pathways

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