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MIC 205A Exam 2 Questions and Correct
Answers/ Latest Update / Already Graded
Although the actual procedure is much more involved, the basic
metabolism of wine-making involves inoculating grape juice with a
special strain of the yeast Saccharomyces cerevisiae. S. cerevisiae will
preferentially perform aerobic respiration on sugars in the juice but can
also ferment those sugars to yield CO2 and alcohol, an important
component of wine. Assume you inoculate a completely full container
of juice and then close the lid. What will the yeast do?
Ans: They will grow aerobically, consume the O2 dissolved in
juice, and then switch to fermenting sugars yield alcohol
Which of the following are examples of biofilms?
Ans:
You inoculate a flask containing a complex medium with a culture of
bacteria and use a spectrophotometer to measure the absorbance of
the culture to detect growth. Initial measurements show a modest
turbidity (cloudiness) that remains unchanged for the first few hours,
followed by a steady increase for the rest of the day. Why was there
this delay in growth following inoculation?
Ans:
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You are setting up an enrichment culture to look for methylotrophic
bacteria in a sample of water from Lake Washington in Seattle.
Methylotrophs are capable of obtaining their carbon and energy needs
from single carbon compounds such as methanol. In your enrichment
culture, you provide methanol and a variety of macro- and micro-
nutrients to encourage growth. However, which of the following must
you leave out if you are to successfully enrich for methylotrophs?
Ans: Any other carbon source
You leave several tomatoes in your refrigerator when you go on
vacation. When you get home, the tomatoes are covered in microbial
growth. Select ALL the characteristics you can assign to these
microbes.
Ans: Fastidious
Following the Exxon Valdez oil spill, beaches in Prince William Sound
were treated with nitrogen compounds in order to enhance the
bioremediation of the oil. What does this tell you about the ecosystem
of these beaches?
Ans: When the arrival of large quantities of hydrocarbon,
nitrogen was a limiting for microbial growth
Some enzymes require a cofactor or a coenzyme in order to be active.
What is the difference between cofactors and coenzymes?
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Ans: Cofactors are non-protein components that assist
enzymes and are typically trace elements; coenzymes are
organic cofactors that loosely carry molecules or electrons
Streptococcus pneumoniae lacks an electron transport chain.
Therefore, S. pneumoniae generates ATP via ______.
Ans: Fermentation
Consider how an aerobically respiring bacterial cell uses glycolysis, the
TCA cycle, and oxidative phosphorylation to break apart and oxidize
glucose. What are the three main benefits these central metabolic
pathways yield to the cell?
Ans: ATP, reduced electron carriers, and precursor metabolites
You are studying the metabolism of the phototrophic green sulfur
bacterium Chlorobaculum tepidum and realize that it is running a
reversed TCA cycle! How do you explain this observation?
Ans: C. tepidum is using the reversed TCA cycle to fix CO2
Removing the electron transport chain of E. coli would
Ans: Prevent oxidative phosphorylation
All rights reserved © 2025/ 2026 |
MIC 205A Exam 2 Questions and Correct
Answers/ Latest Update / Already Graded
Although the actual procedure is much more involved, the basic
metabolism of wine-making involves inoculating grape juice with a
special strain of the yeast Saccharomyces cerevisiae. S. cerevisiae will
preferentially perform aerobic respiration on sugars in the juice but can
also ferment those sugars to yield CO2 and alcohol, an important
component of wine. Assume you inoculate a completely full container
of juice and then close the lid. What will the yeast do?
Ans: They will grow aerobically, consume the O2 dissolved in
juice, and then switch to fermenting sugars yield alcohol
Which of the following are examples of biofilms?
Ans:
You inoculate a flask containing a complex medium with a culture of
bacteria and use a spectrophotometer to measure the absorbance of
the culture to detect growth. Initial measurements show a modest
turbidity (cloudiness) that remains unchanged for the first few hours,
followed by a steady increase for the rest of the day. Why was there
this delay in growth following inoculation?
Ans:
All rights reserved © 2025/ 2026 |
, Page |2
You are setting up an enrichment culture to look for methylotrophic
bacteria in a sample of water from Lake Washington in Seattle.
Methylotrophs are capable of obtaining their carbon and energy needs
from single carbon compounds such as methanol. In your enrichment
culture, you provide methanol and a variety of macro- and micro-
nutrients to encourage growth. However, which of the following must
you leave out if you are to successfully enrich for methylotrophs?
Ans: Any other carbon source
You leave several tomatoes in your refrigerator when you go on
vacation. When you get home, the tomatoes are covered in microbial
growth. Select ALL the characteristics you can assign to these
microbes.
Ans: Fastidious
Following the Exxon Valdez oil spill, beaches in Prince William Sound
were treated with nitrogen compounds in order to enhance the
bioremediation of the oil. What does this tell you about the ecosystem
of these beaches?
Ans: When the arrival of large quantities of hydrocarbon,
nitrogen was a limiting for microbial growth
Some enzymes require a cofactor or a coenzyme in order to be active.
What is the difference between cofactors and coenzymes?
All rights reserved © 2025/ 2026 |
, Page |3
Ans: Cofactors are non-protein components that assist
enzymes and are typically trace elements; coenzymes are
organic cofactors that loosely carry molecules or electrons
Streptococcus pneumoniae lacks an electron transport chain.
Therefore, S. pneumoniae generates ATP via ______.
Ans: Fermentation
Consider how an aerobically respiring bacterial cell uses glycolysis, the
TCA cycle, and oxidative phosphorylation to break apart and oxidize
glucose. What are the three main benefits these central metabolic
pathways yield to the cell?
Ans: ATP, reduced electron carriers, and precursor metabolites
You are studying the metabolism of the phototrophic green sulfur
bacterium Chlorobaculum tepidum and realize that it is running a
reversed TCA cycle! How do you explain this observation?
Ans: C. tepidum is using the reversed TCA cycle to fix CO2
Removing the electron transport chain of E. coli would
Ans: Prevent oxidative phosphorylation
All rights reserved © 2025/ 2026 |
