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

A patient is diagnosed with a bacterial infection. The bacteria are found to be using the Entner-Doudoroff pathway. What is a likely consequence of this pathway compared to glycolysis?

Accepted Answer

The bacteria will generate less ATP per glucose molecule than if they used glycolysis.

Question 3

Which of the following statements about ATP is correct?

Accepted Answer

ATP acts as an energy intermediate, storing energy released from catabolic reactions and providing it for anabolic reactions.

Question 4

A researcher adds a competitive inhibitor to an enzyme-catalyzed reaction. What is the most likely effect on the reaction rate, and how can it be overcome?

Accepted Answer

The reaction rate will decrease, but increasing substrate concentration can restore the rate.

Question 5

Which of the following equations correctly represents the net ATP yield from aerobic respiration of one molecule of glucose in prokaryotes?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + 38ATP$$

Question 6

Why are hyperthermophiles that grow at temperatures above 100°C seemingly limited to oceanic depths?

Accepted Answer

The high pressure at oceanic depths prevents water from boiling, allowing hyperthermophiles to survive at temperatures above 100°C.

Question 7

A microbiologist is culturing bacteria in a medium containing radioactive sulfur ($$^{35}S). In $$which cellular molecules will the $$^{35}S$$ most likely be found?

Accepted Answer

Proteins

Question 8

Which of the following best explains why gram-negative bacteria are generally more resistant to chemical biocides than gram-positive bacteria?

Accepted Answer

Gram-negative bacteria have an outer membrane that acts as a barrier to many chemicals.

Question 9

Which of the following is a correct statement about feedback inhibition in metabolic pathways?

Accepted Answer

Feedback inhibition is usually a form of noncompetitive inhibition, where the end product binds to an allosteric site on an enzyme.

Question 10

A hospital is trying to sterilize surgical instruments. Which of the following methods would be most effective for killing endospores?

Accepted Answer

Autoclaving at $$121^{\circ}C$ and 15 psi for 15 minutes

Question 11

Which of the following best describes the chemiosmotic model for ATP generation?

Accepted Answer

ATP is generated as protons flow down their electrochemical gradient through ATP synthase.

Question 12

A laboratory technician is using the streak plate method to isolate bacteria. What is the primary purpose of this technique?

Accepted Answer

To obtain pure cultures by physically separating individual bacterial cells on the agar surface.

Question 13

Which of the following is a real-world example of the use of osmotic pressure to control microbial growth?

Accepted Answer

Salting fish to preserve it by drawing water out of microbial cells.

Question 14

Which of the following best explains why alcohol is effective against some viruses but not others?

Accepted Answer

Alcohol disrupts lipid envelopes, so it is effective against enveloped viruses but not non-enveloped viruses.

Question 15

Which of the following is a correct summary of energy production in cells?

Accepted Answer

Cells obtain energy by oxidizing molecules such as glucose, sulfur, or using sunlight, transferring electrons to generate ATP.

Question 16

A patient sample is tested for the presence of Escherichia coli and Pseudomonas aeruginosa. Which biochemical test would best differentiate these two bacteria?

Accepted Answer

The ability to ferment lactose

Question 17

Which of the following statements about biofilms is correct?

Accepted Answer

Biofilms protect bacteria from antibiotics and the immune system, making infections harder to treat.

Question 18

Which of the following best describes the difference between sterilization and disinfection?

Accepted Answer

Sterilization destroys all forms of microbial life, while disinfection eliminates most pathogens but not necessarily all microbes or spores.

Question 19

Which of the following is a correct statement about the phases of microbial growth in batch culture?

Accepted Answer

During the stationary phase, the rate of cell growth equals the rate of cell death.

Question 20

Which of the following best explains why a solution containing a million bacteria takes longer to sterilize than one containing a half-million bacteria, assuming the same treatment conditions?

Accepted Answer

Microbial death occurs at a constant rate, so more bacteria require more time to reach zero survivors.

Microbiology Study Guide: Chapters 5, 6, and 7 – Step-by-Step Guidance

Study Guide - Practice Questions

Study Guide - Flashcards