Question 1

In fermentation, the only ATP produced was during glycolysis and the fermentation reactions usually result in converting NADH to NAD.

Accepted Answer

A) True 
 B)False

Question 2

Most enzymes function best at

Accepted Answer

A)  acidic pH and high salt concentrations. 
B)  basic pH and low salt concentrations. 
C)  slightly above pH 7 and low salt concentrations. 
D)  neutral pH and high salt concentrations. 
E)  slightly above pH 7 and high salt concentrations. 
A)  acidic pH and high salt concentrations. 
B)  basic pH and low salt concentrations. 
C)  slightly above pH 7 and low salt concentrations. 
D)  neutral pH and high salt concentrations. 
E)  slightly above pH 7 and high salt concentrations.

Question 3

Anoxygenic photosynthetic bacteria

Accepted Answer

A)  obtain electrons from water. 
B)  produce oxygen as a by-product. 
C)  may obtain electrons from H₂S. 
D)  are obligate aerobes. 
E)  produce oxygen as a by-product AND may obtain electrons from H₂S. 
A)  obtain electrons from water. 
B)  produce oxygen as a by-product. 
C)  may obtain electrons from H₂S. 
D)  are obligate aerobes. 
E)  produce oxygen as a by-product AND may obtain electrons from H₂S.

Question 4

Biosynthetic reactions that require energy for the conversion of molecular subunits into larger molecules are called

Accepted Answer

A)  kinetic energy. 
B)  anabolic reactions. 
C)  catabolic reactions. 
D)  precursor molecules. 
E)  canabolic reactions. 
A)  kinetic energy. 
B)  anabolic reactions. 
C)  catabolic reactions. 
D)  precursor molecules. 
E)  canabolic reactions.

Question 5

The mutual interaction of substrate and enzyme is described as a(n)

Accepted Answer

A)  lock and key arrangement. 
B)  induced fit. 
C)  active site. 
D)  allosteric site. 
E)  active site AND allosteric site. 
A)  lock and key arrangement. 
B)  induced fit. 
C)  active site. 
D)  allosteric site. 
E)  active site AND allosteric site.

Question 6

Please select the False statement regarding the central metabolic pathways.

Accepted Answer

A)  Glycolysis oxidizes glucose to pyruvate, yielding some ATP and NADH, and six different precursor metabolites. 
B)  The pentose phosphate pathway oxidizes glucose, producing two different precursor metabolites and NADPH for biosynthesis. 
C)  The transition step and TCA cycle complete the oxidation of glucose, yielding ATP,  reducing power, and three different precursor metabolites. 
D)  The transition step and TCA cycle are repeated four times to yield ATP,  reducing power, and three different precursor metabolites. 
E)  Two molecules of acetyl-CoA are generated for each glucose molecule that enters glycolysis, so the breakdown of one molecule of glucose causes the TCA cycle to turn twice. 
A)  Glycolysis oxidizes glucose to pyruvate, yielding some ATP and NADH, and six different precursor metabolites. 
B)  The pentose phosphate pathway oxidizes glucose, producing two different precursor metabolites and NADPH for biosynthesis. 
C)  The transition step and TCA cycle complete the oxidation of glucose, yielding ATP,  reducing power, and three different precursor metabolites. 
D)  The transition step and TCA cycle are repeated four times to yield ATP,  reducing power, and three different precursor metabolites. 
E)  Two molecules of acetyl-CoA are generated for each glucose molecule that enters glycolysis, so the breakdown of one molecule of glucose causes the TCA cycle to turn twice.

Question 7

Glycolysis

Accepted Answer

A)  requires oxygen. 
B)  may occur under aerobic or anaerobic conditions. 
C)  produces 3 ATP molecules per molecule glucose. 
D)  produces 4 molecules of NAD per molecule glucose. 
E)  always occurs under aerobic conditions. 
A)  requires oxygen. 
B)  may occur under aerobic or anaerobic conditions. 
C)  produces 3 ATP molecules per molecule glucose. 
D)  produces 4 molecules of NAD per molecule glucose. 
E)  always occurs under aerobic conditions.

Question 8

Your brother has a bacterial infection. He tells you he going to the gym where he plans to sit in the sauna for an hour. He thinks that this will cure his infection, because the heat in the sauna will denature the enzymes of the bacteria making him ill. You are a nursing student who is currently studying microbiology. You tell him that

Accepted Answer

A)  his plan is sure to work because pathogens are mesophiles, so their enzymes will definitely become denatured and stop working. 
B)  his plan won't work; homeostasis will keep his body temperature constant even in the sauna, so the bacteria (and his normal microbiota and body cells) will not be impacted. 
C)  his plan will work because his body temperature will likely rise to about 60ᵒC in the sauna, which is enough to denature the pathogen's enzymes. 
D)  his plan will work; the organism causing his illness will likely dehydrate and be killed in the sauna but he is probably going to contract a different pathogen in that environment. 
E)  his plan won't work; most pathogens are thermophiles so the temperature of the sauna will not affect the enzymes of the organism causing his illness. 
A)  his plan is sure to work because pathogens are mesophiles, so their enzymes will definitely become denatured and stop working. 
B)  his plan won't work; homeostasis will keep his body temperature constant even in the sauna, so the bacteria (and his normal microbiota and body cells) will not be impacted. 
C)  his plan will work because his body temperature will likely rise to about 60ᵒC in the sauna, which is enough to denature the pathogen's enzymes. 
D)  his plan will work; the organism causing his illness will likely dehydrate and be killed in the sauna but he is probably going to contract a different pathogen in that environment. 
E)  his plan won't work; most pathogens are thermophiles so the temperature of the sauna will not affect the enzymes of the organism causing his illness.

Question 9

Exergonic reactions

Accepted Answer

A)  occur when there is more free energy in the products than the reactants. 
B)  occur when there is more free energy in the reactants than the products. 
C)  are defined as a decrease in entropy. 
D)  are chemoorganotrophic. 
E)  are defined as a decrease in energy AND are chemoorganotrophic. 
A)  occur when there is more free energy in the products than the reactants. 
B)  occur when there is more free energy in the reactants than the products. 
C)  are defined as a decrease in entropy. 
D)  are chemoorganotrophic. 
E)  are defined as a decrease in energy AND are chemoorganotrophic.

Question 10

A student argued that aerobic and anaerobic respiration should produce the same amount of energy. He argued that both processes are essentially the same-only the terminal electron acceptor is different. What's wrong with his argument?

Accepted Answer

A)  Nothing-they SHOULD both produce the same amount of energy. Clearly he knows more than his professors or the writers of his textbook. 
B)  Not all electrons are brought into the electron transport chain with the same amounts of potential energy. NADH, for example, enters the electron transport chain "further up" than FADH₂-so it will lead to less proton motive force being generated, and thus less eventual ATP. 
C)  Not all electron acceptors are the same-some are closer in terms of electronegativity to their high-energy electron carrier molecules (e.g., NADH) than others, and this impacts the amount of produced energy. Oxygen has the highest electron affinity of the terminal electron acceptors used. 
D)  He should believe what his instructors tell him, without question-and they say aerobic respiration is better, so it MUST be so. 
A)  Nothing-they SHOULD both produce the same amount of energy. Clearly he knows more than his professors or the writers of his textbook. 
B)  Not all electrons are brought into the electron transport chain with the same amounts of potential energy. NADH, for example, enters the electron transport chain "further up" than FADH₂-so it will lead to less proton motive force being generated, and thus less eventual ATP. 
C)  Not all electron acceptors are the same-some are closer in terms of electronegativity to their high-energy electron carrier molecules (e.g., NADH) than others, and this impacts the amount of produced energy. Oxygen has the highest electron affinity of the terminal electron acceptors used. 
D)  He should believe what his instructors tell him, without question-and they say aerobic respiration is better, so it MUST be so.

Question 11

The readily usable energy currency of cells is

Accepted Answer

A)  electricity. 
B)  the electron transport system. 
C)  ATP. 
D)  CTP. 
E)  the electron transport system AND CTP. 
A)  electricity. 
B)  the electron transport system. 
C)  ATP. 
D)  CTP. 
E)  the electron transport system AND CTP.

Question 12

Studies done by Buchner showed that ground-up yeast cells were able to convert sugar to alcohol. The components of the mixture that were responsible for this transformation were

Accepted Answer

A)  DNA molecules. 
B)  enzymes. 
C)  lipids. 
D)  carbohydrates. 
E)  phospholipids. 
A)  DNA molecules. 
B)  enzymes. 
C)  lipids. 
D)  carbohydrates. 
E)  phospholipids.

Question 13

Tetrathionate broth is an enrichment medium. Initially, when a mixed bacterial stool sample is inoculated into this medium, the bacteria respire aerobically. Once O₂ is depleted, most bacteria switch to fermentation in order to continue growth. However, Salmonella can use the tetrathionate in this medium as a terminal electron acceptor, so can grow anaerobically. Why does this give the bacteria a competitive advantage over other bacteria in the sample?

Accepted Answer

A)  Tetrathionate inhibits the growth of fermenters. 
B)  Fermentation yields more ATP than aerobic respiration. 
C)  Anaerobic respiration yields more ATP than aerobic respiration. 
D)  Anaerobic respiration yields more ATP than fermentation. 
E)  Tetrathionate yields more ATP than glucose. 
A)  Tetrathionate inhibits the growth of fermenters. 
B)  Fermentation yields more ATP than aerobic respiration. 
C)  Anaerobic respiration yields more ATP than aerobic respiration. 
D)  Anaerobic respiration yields more ATP than fermentation. 
E)  Tetrathionate yields more ATP than glucose.

Question 14

What is the effect of poisons such as mercury in antimicrobial products? Recall that mercury oxidizes the S-H groups of the amino acid cysteine in proteins, converting it to cystine.

Accepted Answer

A)  Competitive inhibition-the mercury binds to the active site of a bacterial enzyme, inhibiting the function of the enzyme. 
B)  Reversible non-competitive inhibition-the mercury binds to an allosteric site on a bacterial enzyme, changing the active site shape temporarily and inhibiting enzyme function. 
C)  Irreversible non-competitive inhibition-the mercury binds to an allosteric site on the enzyme and permanently changes the shape of the active site, so that the enzyme becomes nonfunctional. 
D)  Reversible non-competitive inhibition-the mercury binds to the active site of an enzyme temporarily, inhibiting its function. 
E)  Competitive inhibition-the mercury binds to an allosteric site on a bacterial enzyme, blocking attachment of the appropriate substrate and inhibiting the function of the enzyme. 
A)  Competitive inhibition-the mercury binds to the active site of a bacterial enzyme, inhibiting the function of the enzyme. 
B)  Reversible non-competitive inhibition-the mercury binds to an allosteric site on a bacterial enzyme, changing the active site shape temporarily and inhibiting enzyme function. 
C)  Irreversible non-competitive inhibition-the mercury binds to an allosteric site on the enzyme and permanently changes the shape of the active site, so that the enzyme becomes nonfunctional. 
D)  Reversible non-competitive inhibition-the mercury binds to the active site of an enzyme temporarily, inhibiting its function. 
E)  Competitive inhibition-the mercury binds to an allosteric site on a bacterial enzyme, blocking attachment of the appropriate substrate and inhibiting the function of the enzyme.

Question 15

Which pair is correctly matched, regarding electron transport carriers in eukaryotes?

Accepted Answer

A)  Complex I - succinate dehydrogenase complex 
B)  Complex II - cytochrome c oxidase complex 
C)  Complex III - cytochrome bc₁ complex 
D)  Complex IV - NADH dehydrogenase complex 
E)  None of the answer choices is correct. 
A)  Complex I - succinate dehydrogenase complex 
B)  Complex II - cytochrome c oxidase complex 
C)  Complex III - cytochrome bc₁ complex 
D)  Complex IV - NADH dehydrogenase complex 
E)  None of the answer choices is correct.

Question 16

Which type of phosphorylation does not require a membrane?

Accepted Answer

A)  Substrate-level phosphorylation 
B)  Oxidative phosphorylation 
C)  Photophosphorylation 
D)  All types of phosphorylation require a membrane. 
E)  Phosphorylation never requires a membrane. 
A)  Substrate-level phosphorylation 
B)  Oxidative phosphorylation 
C)  Photophosphorylation 
D)  All types of phosphorylation require a membrane. 
E)  Phosphorylation never requires a membrane.

Question 17

Glycolysis, the Entner-Duodoroff pathway, and the pentose phosphate pathway all produce

Accepted Answer

A)  pyruvate. 
B)  NAD. 
C)  NADP. 
D)  acetyl-CoA. 
E)  pyrite. 
A)  pyruvate. 
B)  NAD. 
C)  NADP. 
D)  acetyl-CoA. 
E)  pyrite.

Question 18

Please select the True statement regarding metabolic processes.

Accepted Answer

A)  Anabolic processes degrade subunits of macromolecules, using ATP and precursor metabolites. 
B)  Catabolic processes harvest the energy released during breakdown of compounds to synthesize ATP. 
C)  Anabolic processes assemble subunits of macromolecules, releasing ATP and precursor metabolites. 
D)  Catabolic processes harvest the energy released during synthesis of compounds to break down ATP. 
E)  Anabolic and catabolic processes have no relation to each other; they function completely independently. 
A)  Anabolic processes degrade subunits of macromolecules, using ATP and precursor metabolites. 
B)  Catabolic processes harvest the energy released during breakdown of compounds to synthesize ATP. 
C)  Anabolic processes assemble subunits of macromolecules, releasing ATP and precursor metabolites. 
D)  Catabolic processes harvest the energy released during synthesis of compounds to break down ATP. 
E)  Anabolic and catabolic processes have no relation to each other; they function completely independently.

Question 19

The TCA cycle produces

Accepted Answer

A)  ATP, FAD, and precursor metabolites 
B)  NADH, ATP,  and FAD. 
C)  FADH₂, NADH, and precursor metabolites. 
D)  FADH₂, ADP, and NADH. 
E)  precursor metabolites, NAD, and FADH₂. 
A)  ATP, FAD, and precursor metabolites 
B)  NADH, ATP,  and FAD. 
C)  FADH₂, NADH, and precursor metabolites. 
D)  FADH₂, ADP, and NADH. 
E)  precursor metabolites, NAD, and FADH₂.

Question 20

The Calvin cycle produces six ATP for every six turns of the cycle.

Accepted Answer

A) True 
 B)False

Exam 6: Microbial Metabolism: Fueling Cell Growth

In fermentation, the only ATP produced was during glycolysis and the fermentation reactions usually result in converting NADH to NAD.

Most enzymes function best at

Anoxygenic photosynthetic bacteria

Biosynthetic reactions that require energy for the conversion of molecular subunits into larger molecules are called

The mutual interaction of substrate and enzyme is described as a(n)

Please select the False statement regarding the central metabolic pathways.

Glycolysis

Exergonic reactions

A student argued that aerobic and anaerobic respiration should produce the same amount of energy. He argued that both processes are essentially the same-only the terminal electron acceptor is different. What's wrong with his argument?

The readily usable energy currency of cells is

Studies done by Buchner showed that ground-up yeast cells were able to convert sugar to alcohol. The components of the mixture that were responsible for this transformation were

What is the effect of poisons such as mercury in antimicrobial products? Recall that mercury oxidizes the S-H groups of the amino acid cysteine in proteins, converting it to cystine.

Which pair is correctly matched, regarding electron transport carriers in eukaryotes?

Which type of phosphorylation does not require a membrane?

Glycolysis, the Entner-Duodoroff pathway, and the pentose phosphate pathway all produce

Please select the True statement regarding metabolic processes.

The TCA cycle produces

The Calvin cycle produces six ATP for every six turns of the cycle.

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Control of Microbial Growth

The Blueprint of Life, from DNA to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

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