Question 1

Describe three mechanisms organisms use to reduce osmotic stress.

Accepted Answer

Compatible solutes can be made or import...

Question 2

The pressure (psi, or pounds per square inch)  at Earth's surface is:

Accepted Answer

A)   0 psi
B)   3 psi
C)   5 psi
D)   7 psi
E)   14 psiF) A) and B)
G) A) and C)

Question 3

The general result of the Arrhenius equation is that growth rate roughly doubles for every __________°C rise in temperature.

Accepted Answer

A)   5
B)   10
C)   15
D)   20
E)   25F) A) and B)
G) A) and C)

Question 4

__________ grow at temperatures as high as 121°C, which occur under extreme pressure.

Accepted Answer

A)   Thermophiles
B)   Extreme halophiles
C)   Psychrophiles
D)   Hyperpsychrophiles
E)   HyperthermophilesF) A) and C)
G) A) and E)

Question 5

____________________ is one of the important signaling molecules that controls global gene expression during starvation.

Accepted Answer

A)   Cyclic AMP
B)   ADP
C)   ATP
D)   Glucose
E)   WaterF) B) and E)
G) A) and E)

Question 6

Which of the following is true of microbes and their membranes?

Accepted Answer

A)   They are relatively permeable to protons.
B)   Protons can leak through directly when the difference in intracellular and extracellular pH is very high.
C)   Membrane-permeant organic acids can prevent the leakage of protons.
D)   They are able to change the pH optima of their enzymes.
E)   Acidophiles use Na+/H+ antiporters to remove internal protons.F) C) and D)
G) None of the above

Question 7

__________ are prominent flora beneath icebergs in the Arctic and Antarctic.

Accepted Answer

A)   Barophiles
B)   Psychrophiles
C)   Mesophiles
D)   Thermophiles
E)   AcidophilesF) B) and E)
G) D) and E)

Question 8

Why are many barophiles also psychrophiles, and how are the adaptations for barophiles and psychrophiles similar?

Accepted Answer

Barophiles are typically found on the oc...

Question 9

Why are thermophiles able to survive at temperatures that would quickly kill most mesophiles? Describe at least three adaptations.

Accepted Answer

Thermophilic proteins are more stable du...

Question 10

Human pathogens are:

Accepted Answer

A)   halophiles
B)   psychrophiles
C)   mesophiles
D)   thermophiles
E)   extreme thermophilesF) C) and D)
G) A) and E)

Question 11

A virus that kills bacteria is called a:

Accepted Answer

A)   bacteriophage
B)   viroid
C)   spore
D)   probiotic
E)   porinF) B) and C)
G) None of the above

Question 12

How does pH affect proteins? Why do proteins have an optimum, minimum, and maximum pH at which they will function?

Accepted Answer

The charges on amino or carboxyl groups ...

Question 13

During the starvation response, most organisms can do all of the following EXCEPT:

Accepted Answer

A)   retool transport systems for the uptake of different nutrients
B)   form metabolically inactive endospores
C)   protect against reactive oxygen species
D)   protect against temperature extremes
E)   protect against pH extremesF) A) and C)
G) A) and E)

Question 14

Which best describes microaerophiles?

Accepted Answer

A)   They require atmospheric oxygen levels to grow.
B)   They cannot grow in the presence of oxygen.
C)   They will use oxygen if it is present, but can grow even if oxygen is not present.
D)   They require a small amount of oxygen.
E)   They can't use oxygen to grow, but oxygen won't kill them.F) None of the above
G) A) and B)

Question 15

Most bacteria require water activity to be greater than:

Accepted Answer

A)   0.10
B)   0.25
C)   0.74
D)   0.91
E)   1.0F) B) and E)
G) D) and E)

Question 16

Which of the following is NOT true of proton motive force in bacteria?

Accepted Answer

A)   It is used in the generation of energy in the form of ADP.
B)   It is used to turn the flagellar motor.
C)   It can be used for nutrient transport.
D)   It produces a transmembrane electrochemical gradient.
E)   All of the above are true.F) B) and D)
G) B) and E)

Question 17

Give an example of a naturally occurring organic acid stress situation in the food industry. How does the food industry mimic this, and why?

Accepted Answer

In the yogurt-making process, lactobacil...

Question 18

Which temperature is quickly lethal to any mesophile?

Accepted Answer

A)   its optimum growth temperature
B)   its minimum growth temperature
C)   its maximum growth temperature
D)   refrigeration temperature
E)   autoclave temperatureF) All of the above
G) C) and E)

Question 19

The type of antimicrobial drug that would be least toxic to humans is a drug that:

Accepted Answer

A)   inhibits protein synthesis
B)   disrupts the cytoplasmic membrane
C)   inhibits nucleic acid synthesis
D)   inhibits metabolic pathways
E)   inhibits cell wall synthesisF) All of the above
G) A) and E)

Question 20

How is the phenol coefficient calculated? Why is phenol the standard for testing other disinfectants?

Accepted Answer

Because of its potency and its history, ...

Exam 5: Environmental Influences and Control of Microbial Growth

A virus that kills bacteria is called a:

Correct AnswerverifiedShow Answer

Describe three mechanisms organisms use to reduce osmotic stress.

Correct AnswerverifiedCompatible solutes can be made or import...View AnswerShow Answer

Which best describes microaerophiles?

Correct AnswerverifiedShow Answer

Give an example of a naturally occurring organic acid stress situation in the food industry. How does the food industry mimic this, and why?

Correct AnswerverifiedIn the yogurt-making process, lactobacil...View AnswerShow Answer

The pressure (psi, or pounds per square inch) at Earth's surface is:

Correct AnswerverifiedShow Answer

____________________ is one of the important signaling molecules that controls global gene expression during starvation.

Correct AnswerverifiedShow Answer

During the starvation response, most organisms can do all of the following EXCEPT:

Correct AnswerverifiedShow Answer

Why are thermophiles able to survive at temperatures that would quickly kill most mesophiles? Describe at least three adaptations.

Correct AnswerverifiedThermophilic proteins are more stable du...View AnswerShow Answer

Human pathogens are:

Correct AnswerverifiedShow Answer

Which temperature is quickly lethal to any mesophile?

Correct AnswerverifiedShow Answer

The general result of the Arrhenius equation is that growth rate roughly doubles for every __________°C rise in temperature.

Correct AnswerverifiedShow Answer

__________ are prominent flora beneath icebergs in the Arctic and Antarctic.

Correct AnswerverifiedShow Answer

Which of the following is NOT true of proton motive force in bacteria?

Correct AnswerverifiedShow Answer

Most bacteria require water activity to be greater than:

Correct AnswerverifiedShow Answer

The type of antimicrobial drug that would be least toxic to humans is a drug that:

Correct AnswerverifiedShow Answer

How does pH affect proteins? Why do proteins have an optimum, minimum, and maximum pH at which they will function?

Correct AnswerverifiedThe charges on amino or carboxyl groups ...View AnswerShow Answer

How is the phenol coefficient calculated? Why is phenol the standard for testing other disinfectants?

Correct AnswerverifiedBecause of its potency and its history, ...View AnswerShow Answer

Which of the following is true of microbes and their membranes?

Correct AnswerverifiedShow Answer

__________ grow at temperatures as high as 121°C, which occur under extreme pressure.

Correct AnswerverifiedShow Answer

Why are many barophiles also psychrophiles, and how are the adaptations for barophiles and psychrophiles similar?

Correct AnswerverifiedBarophiles are typically found on the oc...View AnswerShow Answer

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Compatible solutes can be made or import...
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In the yogurt-making process, lactobacil...
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Thermophilic proteins are more stable du...
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The charges on amino or carboxyl groups ...
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Because of its potency and its history, ...
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Barophiles are typically found on the oc...
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