Question 1

Which of the following best describes the process of substrate-level phosphorylation?

Accepted Answer

ATP is generated directly by transferring a phosphate group from a substrate to ADP.

Question 2

A patient presents with muscle cramps after intense exercise. Which metabolic pathway is primarily responsible for the buildup of lactic acid in their muscles?

Accepted Answer

Fermentation

Question 3

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy required for a reaction to occur.

Question 4

A microbiologist is culturing bacteria in a hypertonic solution. What is the most likely outcome for the bacterial cells?

Accepted Answer

Plasmolysis will occur, causing the cells to shrink.

Question 5

Which phase of the bacterial growth curve is characterized by an equal rate of cell division and cell death?

Accepted Answer

Stationary phase

Question 6

A hospital is testing a new disinfectant using the disk-diffusion method. Which result indicates the disinfectant is most effective?

Accepted Answer

A large zone of inhibition around the disk

Question 7

Which of the following best explains why endospores are difficult to eliminate using standard disinfection methods?

Accepted Answer

Endospores have highly resistant structures that protect them from heat and chemicals.

Question 8

Which of the following equations correctly represents the net ATP yield from glycolysis per molecule of glucose?

Accepted Answer

$$2 \ ATP$$

Question 9

A bacterial culture is exposed to 121°C for 15 minutes in an autoclave. What is the expected outcome?

Accepted Answer

All microbes and endospores will be killed.

Question 10

Which of the following best describes the action of noncompetitive enzyme inhibitors?

Accepted Answer

They bind to an allosteric site, changing the enzyme's shape and reducing activity.

Question 11

A food company uses nitrates and nitrites in processed meats. What is the primary purpose of these additives?

Accepted Answer

To prevent endospore germination and growth of Clostridium botulinum.

Question 12

Which of the following is a correct statement about facultative anaerobes?

Accepted Answer

They grow better in the presence of oxygen but can grow without it.

Question 13

Which chemical agent is most appropriate for sterilizing heat-sensitive medical equipment?

Accepted Answer

Ethylene oxide gas

Question 14

A scientist measures the turbidity of a bacterial culture using a spectrophotometer. What is being measured?

Accepted Answer

The relative cell density based on light absorption.

Question 15

Which of the following best describes the effect of UV light on microbial DNA?

Accepted Answer

It causes thymine dimers, leading to mutations.

Question 16

A bacterial culture is in the log phase of growth. Which of the following best describes what is happening?

Accepted Answer

Cells are dividing at an exponential rate.

Question 17

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

Accepted Answer

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

Question 18

Which of the following best explains why moist heat is generally more effective than dry heat for sterilization?

Accepted Answer

Moist heat penetrates cells better and denatures proteins more efficiently.

Question 19

A laboratory technician is using filtration to sterilize a solution. What is the most likely reason for choosing this method?

Accepted Answer

The solution is heat-sensitive and cannot be autoclaved.

Question 20

Which of the following best describes the effect of a competitive inhibitor on enzyme activity?

Accepted Answer

It binds to the active site, preventing substrate binding.

Microbial Metabolism, Growth, and Control: Study Guide for BIOL 2040 Exam 2 (Chapters 5-7)

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