Question 1

How does bacteriorhodopsin couple photoexcitation with proton pumping? How is ATP synthesized in bacteriorhodopsin-containing organisms?

Accepted Answer

Bacteriorhodopsin is an integral membran...

Question 2

Describe the role of the thylakoids in purple bacteria. Why is it that pumping protons into the lumen is essentially equivalent to pumping protons out of the cell?

Accepted Answer

In bacteria, thylakoids are invagination...

Question 3

What are methanotrophs? What is their role in the global carbon cycle?

Accepted Answer

Methanotrophs are organisms that oxidize...

Question 4

The following is NOT correct about the process of methanogenesis:

Accepted Answer

A)   CO2 and H2O are weak electron acceptors, whereas CH4 and H2 are strong electron donors.
B)   CH4 synthesis from CO2 releases energy for growth.
C)   CH4 and water can be formed from CO2 and 4H2 from a hydrogen donor.
D)   Oxygen atoms in CO2 are reduced one at a time.
E)   Oxygen atoms in CO2 are reduced to water at the same time.F) A) and C)
G) C) and E)

Question 5

The proton motive force drives the following process in bacteria:

Accepted Answer

A)   ATP biosynthesis from ADP and Pi
B)   flagellar rotation
C)   nutrient uptake
D)   all of the above
E)   none of the aboveF) D) and E)
G) A) and B)

Question 6

In anaerobic soils, some yeasts and filamentous fungi can reduce nitrate to nitrite and nitrite to:

Accepted Answer

A)   ammonia (NH3) 
B)   nitric oxide (NO) 
C)   urea
D)   all of the above
E)   none of the aboveF) C) and E)
G) B) and D) B

Question 7

What is dissimilatory metal reduction? How is it different from assimilatory metal reduction?

Accepted Answer

Dissimilatory metal reduction is an impo...

Question 8

Cyanobacteria have __________-based photosynthesis and are the only __________-producing bacteria.

Accepted Answer

A)   H2S; S0
B)   Mg2+; NO
C)   H2O; O2
D)   succinate; O2
E)   none of the aboveF) A) and B)
G) A) and C)

Question 9

Which one of the following enzymes is embedded in the membrane as an ETS component?

Accepted Answer

A)   pyruvate dehydrogenase
B)  2-oxaloglutarate dehydrogenase
C)   succinate dehydrogenase
D)   aconitase
E)   none of the aboveF) C) and D)
G) A) and C)

Question 10

In Rhodospirillum rubrum photosystem II, bacteriochloropyll P870 can absorb weak infrared wavelengths in the __________ range.

Accepted Answer

A)   65-700
B)   750-850
C)   800-1,100
D)   all of the above
E)   none of the aboveF) A) and E)
G) C) and D)

Question 11

Neisseria species are known to use dissimilatory reduction of nitrate to ammonium. How can this reaction be used to distinguish Neisseria gonorrhoeae from other related species?

Accepted Answer

A)   N. gonorrhoeae will test negative for terminal NOreductase.
B)   N. gonorrhoeae will test positive for terminal NOreductase.
C)   All Neisseria species test negative for terminal NOreductase.
D)   None of the enzymes involved in dissimilatory reduction of nitrate are known from Neisseria.
E)   None of the above.F) A) and D)
G) A) and C)

Question 12

What is photoheterotrophy? Give examples of photoheterotrophic organisms.

Accepted Answer

The combination of light absorption to gain energy and heterotrophic use of organic molecules is called photoheterotrophy. Light capture does not replace catabolism for energy or heterotrophy for carbon sources, but it supplements them. Examples of photoheterotrophs include organisms with bacteriorhodopsin-bearing purple membranes, such as the haloarchaean Halobacterium salinarum.

Question 13

Which kind of ion gradient do extreme halophilic archaea exclusively utilize?

Accepted Answer

A)   proton
B)   sodium ion
C)   potassium ion
D)   calcium ion
E)   magnesium ionF) D) and E)
G) B) and C)

Question 14

Enzymes transferring electrons at the start of the ETS are referred to as __________, whereas enzymes transferring electrons to the terminal electron acceptor are designated __________.

Accepted Answer

A)   dehydrogenases; oxidases
B)   oxidases; dehydrogenases
C)   sulfatases; nitrogenases
D)   none of the above
E)   all of the aboveF) A) and C)
G) D) and E)

Question 15

Which of the following can be used to measure  Δ\DeltaΔ pH?

Accepted Answer

A)   lipid-soluble cations
B)   membrane-permeant weak acids
C)   oxidoreductases
D)   cytochromes
E)   electron acceptors F) B) and D)
G) C) and D)

Question 16

Bacterial cells use various membrane pumps and metabolic pathways to adjust and maintain their proton motive force at a size sufficient to drive ATP synthesis and other processes. Why should the proton motive force (PMF) not be larger than necessary? Give an example of a factor affecting PMF generation.

Accepted Answer

The proton motive force should not be to...

Question 17

What is the chromophore group in bacteriorhodopsin?

Accepted Answer

A)   tochopherol
B)    β\betaβ -carotene
C)   folic acid
D)   retinal
E)   none of the above F) C) and E)
G) B) and D)

Question 18

In seawater, sulfate is the most common anion after chloride. The following is correct with respect to the use of oxidized sulfate by some bacterial groups:

Accepted Answer

A)   Oxidized sulfur molecules have potentials lower than those of the nitrogen series.
B)   Oxidized sulfur molecules such as sulfate and sulfite serve as electron acceptors.
C)   Sulfate and sulfite can receive electrons from hydrocarbons.
D)   Sulfate-reducing archaea and bacteria are widespread in the ocean.
E)   All of the above.F) A) and C)
G) D) and E) E

Question 19

Which of the following is NOT a redox pair?

Accepted Answer

A)   fumarate/succinate
B)   NADH/NAD+,
C)   H2S/H2O
D)   quinone/quinol (Q/QH2) 
E)   FAD/FADH2F) B) and D)
G) A) and D)

Question 20

The F1Fo ATP synthase is a remarkably complex enzymatic complex, its subunit structure highly conserved across life domains. Is it possible to use this enzyme as an antibiotic target?

Accepted Answer

Differences among prokaryotic F₁F_o ATPases...

Exam 14: Respiration, Lithotrophy, and Photolysis

How does bacteriorhodopsin couple photoexcitation with proton pumping? How is ATP synthesized in bacteriorhodopsin-containing organisms?

Correct Answer
verified
Bacteriorhodopsin is an integral membran...
View Answer

Describe the role of the thylakoids in purple bacteria. Why is it that pumping protons into the lumen is essentially equivalent to pumping protons out of the cell?

Correct Answer
verified
In bacteria, thylakoids are invagination...
View Answer

What are methanotrophs? What is their role in the global carbon cycle?

Correct Answer
verified
Methanotrophs are organisms that oxidize...
View Answer

The following is NOT correct about the process of methanogenesis:

Correct Answer
verified

The proton motive force drives the following process in bacteria:

Correct Answer
verified

In anaerobic soils, some yeasts and filamentous fungi can reduce nitrate to nitrite and nitrite to:

Correct Answer
verified
B

What is dissimilatory metal reduction? How is it different from assimilatory metal reduction?

Correct Answer
verified
Dissimilatory metal reduction is an impo...
View Answer

Cyanobacteria have -based photosynthesis and are the only -producing bacteria.

Correct Answer
verified

Which one of the following enzymes is embedded in the membrane as an ETS component?

Correct Answer
verified

In Rhodospirillum rubrum photosystem II, bacteriochloropyll P870 can absorb weak infrared wavelengths in the __________ range.

Correct Answer
verified

Neisseria species are known to use dissimilatory reduction of nitrate to ammonium. How can this reaction be used to distinguish Neisseria gonorrhoeae from other related species?

Correct Answer
verified

What is photoheterotrophy? Give examples of photoheterotrophic organisms.

Which kind of ion gradient do extreme halophilic archaea exclusively utilize?

Correct Answer
verified

Enzymes transferring electrons at the start of the ETS are referred to as , whereas enzymes transferring electrons to the terminal electron acceptor are designated .

Correct Answer
verified

Which of the following can be used to measure $\Delta$ pH?

Correct Answer
verified

Correct Answer
verified
The proton motive force should not be to...
View Answer

What is the chromophore group in bacteriorhodopsin?

Correct Answer
verified

In seawater, sulfate is the most common anion after chloride. The following is correct with respect to the use of oxidized sulfate by some bacterial groups:

Correct Answer
verified
E

Which of the following is NOT a redox pair?

Correct Answer
verified

The F₁F_o ATP synthase is a remarkably complex enzymatic complex, its subunit structure highly conserved across life domains. Is it possible to use this enzyme as an antibiotic target?

Correct Answer
verified
Differences among prokaryotic F₁F_o ATPases...
View Answer

Exam 14: Respiration, Lithotrophy, and Photolysis

How does bacteriorhodopsin couple photoexcitation with proton pumping? How is ATP synthesized in bacteriorhodopsin-containing organisms?

Correct AnswerverifiedBacteriorhodopsin is an integral membran...View AnswerShow Answer

Describe the role of the thylakoids in purple bacteria. Why is it that pumping protons into the lumen is essentially equivalent to pumping protons out of the cell?

Correct AnswerverifiedIn bacteria, thylakoids are invagination...View AnswerShow Answer

What are methanotrophs? What is their role in the global carbon cycle?

Correct AnswerverifiedMethanotrophs are organisms that oxidize...View AnswerShow Answer

The following is NOT correct about the process of methanogenesis:

Correct AnswerverifiedShow Answer

The proton motive force drives the following process in bacteria:

Correct AnswerverifiedShow Answer

In anaerobic soils, some yeasts and filamentous fungi can reduce nitrate to nitrite and nitrite to:

Correct AnswerverifiedB

What is dissimilatory metal reduction? How is it different from assimilatory metal reduction?

Correct AnswerverifiedDissimilatory metal reduction is an impo...View AnswerShow Answer

Cyanobacteria have __________-based photosynthesis and are the only __________-producing bacteria.

Correct AnswerverifiedShow Answer

Which one of the following enzymes is embedded in the membrane as an ETS component?

Correct AnswerverifiedShow Answer

In Rhodospirillum rubrum photosystem II, bacteriochloropyll P870 can absorb weak infrared wavelengths in the __________ range.

Correct AnswerverifiedShow Answer

Neisseria species are known to use dissimilatory reduction of nitrate to ammonium. How can this reaction be used to distinguish Neisseria gonorrhoeae from other related species?

Correct AnswerverifiedShow Answer

What is photoheterotrophy? Give examples of photoheterotrophic organisms.

Which kind of ion gradient do extreme halophilic archaea exclusively utilize?

Correct AnswerverifiedShow Answer

Enzymes transferring electrons at the start of the ETS are referred to as __________, whereas enzymes transferring electrons to the terminal electron acceptor are designated __________.

Correct AnswerverifiedShow Answer

Which of the following can be used to measure Δ\DeltaΔ pH?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedThe proton motive force should not be to...View AnswerShow Answer

What is the chromophore group in bacteriorhodopsin?

Correct AnswerverifiedShow Answer

In seawater, sulfate is the most common anion after chloride. The following is correct with respect to the use of oxidized sulfate by some bacterial groups:

Correct AnswerverifiedE

Which of the following is NOT a redox pair?

Correct AnswerverifiedShow Answer

The F1Fo ATP synthase is a remarkably complex enzymatic complex, its subunit structure highly conserved across life domains. Is it possible to use this enzyme as an antibiotic target?

Correct AnswerverifiedDifferences among prokaryotic F1Fo ATPases...View AnswerShow Answer

Correct Answer
verified
Bacteriorhodopsin is an integral membran...
View Answer

Correct Answer
verified
In bacteria, thylakoids are invagination...
View Answer

Correct Answer
verified
Methanotrophs are organisms that oxidize...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified
Dissimilatory metal reduction is an impo...
View Answer

Cyanobacteria have -based photosynthesis and are the only -producing bacteria.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Enzymes transferring electrons at the start of the ETS are referred to as , whereas enzymes transferring electrons to the terminal electron acceptor are designated .

Correct Answer
verified

Which of the following can be used to measure $\Delta$ pH?

Correct Answer
verified

Correct Answer
verified
The proton motive force should not be to...
View Answer

Correct Answer
verified

Correct Answer
verified
E

Correct Answer
verified

The F₁F_o ATP synthase is a remarkably complex enzymatic complex, its subunit structure highly conserved across life domains. Is it possible to use this enzyme as an antibiotic target?

Correct Answer
verified
Differences among prokaryotic F₁F_o ATPases...
View Answer