Question 1

Which of 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. 
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.

Question 2

What is photoheterotrophy? Give examples of photoheterotrophic organisms.

Accepted Answer

The combination of light absorption to g

Question 3

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 4

Which of the following is NOT a redox pair?

Accepted Answer

A)  fumarate/succinate 
B)  NADH + H+/NAD 
C)  H2S/H2O 
D)  quinone/quinol (Q/QH2) 
E)  FAD/FADH2 
A)  fumarate/succinate 
B)  NADH + H+/NAD 
C)  H2S/H2O 
D)  quinone/quinol (Q/QH2) 
E)  FAD/FADH2

Question 5

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 6

Which of the following is FALSE regarding the ETS in Escherichia coli?

Accepted Answer

A)  NDH-1 is the main initial substrate oxydoreductase; NDH-2 is an alternative NADH dehydrogenase. 
B)  It pumps 10-12 protons per NADH. 
C)  It pumps 2-8 protons per NADH. 
D)  The main terminal oxidase is the cytochrome bo quinol oxidase, which contains heme b, heme O3, and Cu. 
E)  An alternative cytochrome bd quinol oxidase has a higher affinity for oxygen than other terminal oxidases and allows E. coli growth in low-O2 habitats. 
A)  NDH-1 is the main initial substrate oxydoreductase; NDH-2 is an alternative NADH dehydrogenase. 
B)  It pumps 10-12 protons per NADH. 
C)  It pumps 2-8 protons per NADH. 
D)  The main terminal oxidase is the cytochrome bo quinol oxidase, which contains heme b, heme O3, and Cu. 
E)  An alternative cytochrome bd quinol oxidase has a higher affinity for oxygen than other terminal oxidases and allows E. coli growth in low-O2 habitats.

Question 7

The Fₒ portion of Escherichia coli ATP synthase that rotates while translocating protons is
a. the $ \gamma $ drive shaft.
b. subunits a and $ \boldsymbol{b} $.
c. a ring of 8 to $ 15 \mathrm{c} $ subunits.
d. an $ \alpha \beta $-subunit.
e. the catalytic active site.

Accepted Answer

The answer of The Fₒ portion of Escherichia coli ATP...

Question 8

In a redox reaction, the reduction potential E depends on the ratio of product concentrations ([C] and [D]) to reactant concentrations ([A]  and  [B]), as per equation E  =  E°'  -  60  (mV/n)  log  [C][D]/[A][B]. What would be the effect of increasing the ratio of products to reactants by a factor of 10?

Accepted Answer

A)  No effect: E°' assumes 1-M concentrations of reactants and products. 
B)  A change of -60 mV will not modify the estimate of E. 
C)  The value of E will decrease by 60 mV, decreasing energy yield. 
D)  The value of E will increase by 60 mV, increasing energy yield. 
E)  The E°' term is unaffected by changes in concentrations of products or reactants. 
A)  No effect: E°' assumes 1-M concentrations of reactants and products. 
B)  A change of -60 mV will not modify the estimate of E. 
C)  The value of E will decrease by 60 mV, decreasing energy yield. 
D)  The value of E will increase by 60 mV, increasing energy yield. 
E)  The E°' term is unaffected by changes in concentrations of products or reactants.

Question 9

Which of the following is NOT a terminal electron acceptor in anaerobic respirations?

Accepted Answer

A)  nitrate 
B)  nitrite 
C)  hydrogen sulfide 
D)  carbon dioxide 
E)  sulfate 
A)  nitrate 
B)  nitrite 
C)  hydrogen sulfide 
D)  carbon dioxide 
E)  sulfate

Question 10

Which of the following is NOT true of 2,4-dinitrophenol (DNP)?

Accepted Answer

A)  It is an uncoupler. 
B)  It can be used to measure $ \Delta $ pH. 
C)  Unprotonated DNP can cross the membrane. 
D)  Protonated DNP can cross the membrane. 
E) It dissipates the proton motive force. 
A)  It is an uncoupler. 
B)  It can be used to measure $ \Delta $ pH. 
C)  Unprotonated DNP can cross the membrane. 
D)  Protonated DNP can cross the membrane. 
E) It dissipates the proton motive force.

Question 11

In purple bacteria, bacteriochlorophylls are supplemented by accessory pigments called

Accepted Answer

A)  antenna complexes. 
B)  bacteriorhodopsin. 
C)  carotenoids. 
D)  chlorophylls. 
E)  thylakoids. 
A)  antenna complexes. 
B)  bacteriorhodopsin. 
C)  carotenoids. 
D)  chlorophylls. 
E)  thylakoids.

Question 12

In oxygenic photosynthesis, __________ is the electron donor, whereas in anaerobic photosynthesis it can be succinate or __________.

Accepted Answer

A)  H2S; S0 
B)  O2; H2 
C)  O2; H2O 
D)  H2O; H2S 
E)  H2S; SO 
A)  H2S; S0 
B)  O2; H2 
C)  O2; H2O 
D)  H2O; H2S 
E)  H2S; SO

Question 13

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 14

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 15

Which of the following is FALSE regarding dehalorespiration?

Accepted Answer

A)  It is a type of hydrogenotrophy. 
B)  Cl- can be removed from toxic compounds by dehalorespiration. 
C)  Nitrogen (N2) is a by-product of dehalorespiration. 
D)  Halogenated organic molecules serve as electron acceptors for H2. 
E)  Hydrogenotrophs can be used in bioremediation. 
A)  It is a type of hydrogenotrophy. 
B)  Cl- can be removed from toxic compounds by dehalorespiration. 
C)  Nitrogen (N2) is a by-product of dehalorespiration. 
D)  Halogenated organic molecules serve as electron acceptors for H2. 
E)  Hydrogenotrophs can be used in bioremediation.

Question 16

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

Accepted Answer

A)  600-650 
B)  650-700 
C)  700-750 
D)  750-800 
E)  800-1,100 
A)  600-650 
B)  650-700 
C)  700-750 
D)  750-800 
E)  800-1,100

Question 17

How are drug efflux pumps spread among virulent bacterial strains?

Accepted Answer

A)  They are spread through generalized transduction. 
B)  Their genes are contained in plasmids that are transmitted among bacterial cells. 
C)  They are spread through conjugation between two virulent strains. 
D)  They are spread through transformation with Hfr plasmids. 
E)  DNA is released from bacterial cells previously infected with bacteriophages. 
A)  They are spread through generalized transduction. 
B)  Their genes are contained in plasmids that are transmitted among bacterial cells. 
C)  They are spread through conjugation between two virulent strains. 
D)  They are spread through transformation with Hfr plasmids. 
E)  DNA is released from bacterial cells previously infected with bacteriophages.

Question 18

The chemiosmotic theory states that the proton potential is composed of

Accepted Answer

A)  [ATP] and [ADP]+[Pi]. 
B)  a pH gradient and [Na+] gradient. 
C)  pH and pNa+. 
D) $$\Delta$$pH and $$\Delta \Psi$$ 
E)  a pH gradient and a [Ca2+] wave. 
A)  [ATP] and [ADP]+[Pi]. 
B)  a pH gradient and [Na+] gradient. 
C)  pH and pNa+. 
D) $$\Delta$$pH and $$\Delta \Psi$$ 
E)  a pH gradient and a [Ca2+] wave.

Question 19

Use the figure below to describe how an uncoupler functions. Can an uncoupler be used as an antibiotic to treat bacterial infections?

Accepted Answer

An uncoupler can cross the membrane in e

Question 20

Which of the following is FALSE regarding the electron transfer system in mitochondria?

Accepted Answer

A)  The subunits of cytochrome c oxidoreductase (complex IV) are associated to eukaryotic proteins. 
B)  Oxidation of NADH + H+ contributes to the formation of a larger $$\Delta$$p. 
C)  The initial oxidoreductase, the NADH dehydrogenase (complex I), pumps more protons than the NDH-1 in Escherichia coli. 
D)  The succinate dehydrogenase (complex II) contributes to $$\Delta$$p by pumping protons onto the intermembrane space. 
E)  The ETS of some bacteria, such as Paracoccus denitrificans, are organized in a manner similar to that of mitochondria. 
A)  The subunits of cytochrome c oxidoreductase (complex IV) are associated to eukaryotic proteins. 
B)  Oxidation of NADH + H+ contributes to the formation of a larger $$\Delta$$p. 
C)  The initial oxidoreductase, the NADH dehydrogenase (complex I), pumps more protons than the NDH-1 in Escherichia coli. 
D)  The succinate dehydrogenase (complex II) contributes to $$\Delta$$p by pumping protons onto the intermembrane space. 
E)  The ETS of some bacteria, such as Paracoccus denitrificans, are organized in a manner similar to that of mitochondria.

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

Which of the following is NOT correct about the process of methanogenesis?

What is photoheterotrophy? Give examples of photoheterotrophic organisms.

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

Which of the following is NOT a redox pair?

Which of the following is FALSE regarding the ETS in Escherichia coli?

The Fₒ portion of Escherichia coli ATP synthase that rotates while translocating protons is a. the γ \gamma γ drive shaft. b. subunits a and b \boldsymbol{b} b . c. a ring of 8 to 15c 15 \mathrm{c} 15c subunits. d. an αβ \alpha \beta αβ -subunit. e. the catalytic active site.

In a redox reaction, the reduction potential E depends on the ratio of product concentrations ([C] and [D]) to reactant concentrations ([A] and [B]), as per equation E = E°' - 60 (mV/n) log [C][D]/[A][B]. What would be the effect of increasing the ratio of products to reactants by a factor of 10?

Which of the following is NOT a terminal electron acceptor in anaerobic respirations?

Which of the following is NOT true of 2,4-dinitrophenol (DNP)?

In purple bacteria, bacteriochlorophylls are supplemented by accessory pigments called

In oxygenic photosynthesis, __________ is the electron donor, whereas in anaerobic photosynthesis it can be succinate or __________.

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

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

Which of the following is FALSE regarding dehalorespiration?

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

How are drug efflux pumps spread among virulent bacterial strains?

The chemiosmotic theory states that the proton potential is composed of

Use the figure below to describe how an uncoupler functions. Can an uncoupler be used as an antibiotic to treat bacterial infections?

Which of the following is FALSE regarding the electron transfer system in mitochondria?

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

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

Biosynthesis

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

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

Filters

The Fₒ portion of Escherichia coli ATP synthase that rotates while translocating protons is a. the $\gamma$ drive shaft. b. subunits a and $\boldsymbol{b}$ . c. a ring of 8 to $15 \mathrm{c}$ subunits. d. an $\alpha \beta$ -subunit. e. the catalytic active site.

In oxygenic photosynthesis, is the electron donor, whereas in anaerobic photosynthesis it can be succinate or .