Question 1

Which of the following reactions is possible by reverse electron flow?

Accepted Answer

A)  reduction of Fe3+ to Fe2+ 
B)  NADP+ reduction to NADPH 
C)  protein biosynthesis 
D)  reduction of oxygen by Fe2+ to form H₂O and Fe3+ 
E)  anammox 
A)  reduction of Fe3+ to Fe2+ 
B)  NADP+ reduction to NADPH 
C)  protein biosynthesis 
D)  reduction of oxygen by Fe2+ to form H₂O and Fe3+ 
E)  anammox

Question 2

What is the chromophore group in bacteriorhodopsin?

Accepted Answer

A)  tocopherol 
B)  b-carotene 
C)  folic acid 
D)  retinal 
E)  chlorophyll 
A)  tocopherol 
B)  b-carotene 
C)  folic acid 
D)  retinal 
E)  chlorophyll

Question 3

Extreme halophilic archaea exclusively utilize which kind of ion gradient?

Accepted Answer

A)  H+ 
B)  Na+ 
C)  Ca2+ 
D)  K+ 
E)  Mg2+ 
A)  H+ 
B)  Na+ 
C)  Ca2+ 
D)  K+ 
E)  Mg2+

Question 4

Nitrifiers are bacteria

Accepted Answer

A)  that generate nitrites or nitrates. 
B)  that convert N₂ to NH3. 
C)  capable of oxidizing NH3 using NO. 
D)  capable of living in symbiosis in the roots of some plants. 
E)  capable of using NH3 as an electron donor. 
A)  that generate nitrites or nitrates. 
B)  that convert N₂ to NH3. 
C)  capable of oxidizing NH3 using NO. 
D)  capable of living in symbiosis in the roots of some plants. 
E)  capable of using NH3 as an electron donor.

Question 5

While testing the chemiosmotic theory across the domains of life, researchers prepared "inside-out" vesicles from bacterial plasma membranes, mitochondrial internal membranes, and chloroplast thylakoids. An inside-out vesicle is a

Accepted Answer

A)  vesicle in which the F1 subunit of the proton-ATPase faces outward. 
B)  membrane in which the hydrophobic tails of the phospholipids face outward. 
C)  cell that has been enzymatically stripped of its cell wall. 
D)  preparation of outer membranes in Gram-negative bacteria, chloroplast envelopes, and mitochondria outer membranes. 
E)  preparation from bacterial cytoplasm, chloroplast stroma, and mitochondrial matrix. 
A)  vesicle in which the F1 subunit of the proton-ATPase faces outward. 
B)  membrane in which the hydrophobic tails of the phospholipids face outward. 
C)  cell that has been enzymatically stripped of its cell wall. 
D)  preparation of outer membranes in Gram-negative bacteria, chloroplast envelopes, and mitochondria outer membranes. 
E)  preparation from bacterial cytoplasm, chloroplast stroma, and mitochondrial matrix.

Question 6

Is the synthesis of ATP by the F₁Fₒ ATPase reversible? If so, are there any examples?

Accepted Answer

Generation of ATP by the F₁Fₒ ATPase is

Question 7

What is dissimilatory metal reduction? How is it different from assimilatory metal reduction? Is there application of the dissimilatory metal reduction phenomenon?

Accepted Answer

Dissimilatory metal reduction is an impo

Question 8

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)  nitrogen gas (N₂). 
E)  ammonium hydroxide (NH4OH). 
A)  ammonia (NH3). 
B)  nitric oxide (NO). 
C)  urea. 
D)  nitrogen gas (N₂). 
E)  ammonium hydroxide (NH4OH).

Question 9

In cytochromes, the heme group plays a key role in acquiring and transferring electrons with a(n) __________ transition.

Accepted Answer

A)  Mg0/Mg2+ 
B)  S0/S2- 
C)  Cu+/Cu2+ 
D)  Fe3+/Fe2+ 
E)  Mn0/MN₂+ 
A)  Mg0/Mg2+ 
B)  S0/S2- 
C)  Cu+/Cu2+ 
D)  Fe3+/Fe2+ 
E)  Mn0/MN₂+

Question 10

Phototrophy is

Accepted Answer

A)  photolysis. 
B)  use of photoexcited electrons to power cell growth. 
C)  chlorophyll photoexcitation. 
D)  photoionization. 
E)  a charge-separating photopigment. 
A)  photolysis. 
B)  use of photoexcited electrons to power cell growth. 
C)  chlorophyll photoexcitation. 
D)  photoionization. 
E)  a charge-separating photopigment.

Question 11

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

Accepted Answer

Bacteriorhodopsin is an integral membran

Question 12

Ferroplasma acidarmanus produces large amounts of sulfuric acid through

Accepted Answer

A)  oxidation of Cu+ with Cu(NO3)2. 
B)  oxidation of FeS2 with Fe3+ and H₂O. 
C)  oxidation of Fe3O₂ with Fe2+. 
D)  oxidation of H₂S with H₂O. 
E)  reduction of SO with H₂. 
A)  oxidation of Cu+ with Cu(NO3)2. 
B)  oxidation of FeS2 with Fe3+ and H₂O. 
C)  oxidation of Fe3O₂ with Fe2+. 
D)  oxidation of H₂S with H₂O. 
E)  reduction of SO with H₂.

Question 13

Protons can have different fates in bacterial ETS. Which of the following processes does NOT affect the proton motive force (Δp)?

Accepted Answer

A)  Protons are pumped across the membrane (H+) by oxidoreductase complexes. 
B)  Protons are consumed from the cytoplasm by the quinone/quinol pool. 
C)  Protons are released outside the membrane from the quinone/quinol pool. 
D)  Protons are consumed by combining with terminal electron acceptors such as O₂. 
E)  Protons combining with O₂, used as a terminal acceptor, compensate protons released by catabolic pathways. 
A)  Protons are pumped across the membrane (H+) by oxidoreductase complexes. 
B)  Protons are consumed from the cytoplasm by the quinone/quinol pool. 
C)  Protons are released outside the membrane from the quinone/quinol pool. 
D)  Protons are consumed by combining with terminal electron acceptors such as O₂. 
E)  Protons combining with O₂, used as a terminal acceptor, compensate protons released by catabolic pathways.

Question 14

The diagram below shows the structure of the universal FₒF₁ synthase. Which of the following FALSELY labels the figure?

Accepted Answer

A)  i) Fo subunit 
B)  ii) F1 subunit 
C)  iii) catalytic subunit 
D)  iv) subunit a 
E)  v) subunit b 
A)  i) Fo subunit 
B)  ii) F1 subunit 
C)  iii) catalytic subunit 
D)  iv) subunit a 
E)  v) subunit b

Question 15

Neisseria species 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 NO reductase. 
B)  N. gonorrhoeae will test positive for terminal NO reductase. 
C)  All Neisseria species test negative for terminal NO reductase. 
D)  All Neisseria species test positive for terminal NO reductase. 
E)  None of the enzymes involved in dissimilatory reduction of nitrate are known from species of Neisseria. 
A)  N. gonorrhoeae will test negative for terminal NO reductase. 
B)  N. gonorrhoeae will test positive for terminal NO reductase. 
C)  All Neisseria species test negative for terminal NO reductase. 
D)  All Neisseria species test positive for terminal NO reductase. 
E)  None of the enzymes involved in dissimilatory reduction of nitrate are known from species of Neisseria.

Question 16

Electron transport systems are embedded in all of the following membrane systems EXCEPT

Accepted Answer

A)  the mitochondrial inner membrane. 
B)  thylakoids. 
C)  the inner membrane of Gram-negative bacteria. 
D)  the eukaryotic plasma membrane. 
E)  the archaeal plasma membrane. 
A)  the mitochondrial inner membrane. 
B)  thylakoids. 
C)  the inner membrane of Gram-negative bacteria. 
D)  the eukaryotic plasma membrane. 
E)  the archaeal plasma membrane.

Question 17

How does Shewanella oneidensis donate electrons to oxidized minerals in marine sediments?

Accepted Answer

Shewanella oneidensis is a proteobacteri

Question 18

While testing the chemiosmotic theory, rescarchers prepared   vesicles from bacterial
cells, mitochondrial internal membranes, and chloroplast thylakoids. In an inside-out vesicle, the
  subunit of the proton-ATPase faces outward. Using the figure below, briefly discuss how the
use of inside-out vesicles helped to study the relative contributions of the proton gradient  
and the membrane potential   to

Accepted Answer

The answer of While testing the chemiosmotic theory, rescarchers prepared...

Question 19

The figure below represents absorbance spectra of a cytochrome from the membrane of the archaeon Haloferax volcanii. The spectrum from the reduced form is represented by a continuous line and the oxidized form by a dashed line. Describe the differences between the spectra and which wavelength you would use to study the redox reactions of this cytochrome.

Accepted Answer

The reduced form of the cytochrome has t

Question 20

Why and how is it that mitochondria have only a single electron transport system (ETS), unlike many bacteria?

Accepted Answer

Mitochondria have the advantage of exist

Exam 14: Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Which of the following reactions is possible by reverse electron flow?

What is the chromophore group in bacteriorhodopsin?

Extreme halophilic archaea exclusively utilize which kind of ion gradient?

Nitrifiers are bacteria

While testing the chemiosmotic theory across the domains of life, researchers prepared "inside-out" vesicles from bacterial plasma membranes, mitochondrial internal membranes, and chloroplast thylakoids. An inside-out vesicle is a

Is the synthesis of ATP by the F₁Fₒ ATPase reversible? If so, are there any examples?

What is dissimilatory metal reduction? How is it different from assimilatory metal reduction? Is there application of the dissimilatory metal reduction phenomenon?

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

In cytochromes, the heme group plays a key role in acquiring and transferring electrons with a(n) __________ transition.

Phototrophy is

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

Ferroplasma acidarmanus produces large amounts of sulfuric acid through

Protons can have different fates in bacterial ETS. Which of the following processes does NOT affect the proton motive force (Δp)?

The diagram below shows the structure of the universal FₒF₁ synthase. Which of the following FALSELY labels the figure?

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

Electron transport systems are embedded in all of the following membrane systems EXCEPT

How does Shewanella oneidensis donate electrons to oxidized minerals in marine sediments?

Why and how is it that mitochondria have only a single electron transport system (ETS), unlike many bacteria?

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

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Genomes and Chromosomes

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Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

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Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

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