Question 1

What is mixed-acid fermentation? Provide examples of industrial uses of its products.

Accepted Answer

Some enteric bacteria produce a series o

Question 2

All nucleotide triphosphates carry energy. Provide examples of reactions that are driven by the release of energy from GTP, CTP, and TTP.

Accepted Answer

GTP is specifically used in the initiati

Question 3

The laws of thermodynamics indicate that systems tend to become less ordered and that ________, a measure of disorder or randomness of the universe, always increases.

Accepted Answer

A)  entropy 
B)  enthalpy 
C)  Gibbs free energy 
D)  molecular stability 
E)  activation energy 
A)  entropy 
B)  enthalpy 
C)  Gibbs free energy 
D)  molecular stability 
E)  activation energy

Question 4

Escherichia coli degrades human waste in the colon using mixed-acid fermentation. Why is this a factor of concern in some medical procedures, such as colonoscopy?

Accepted Answer

Molecular hydrogen (H₂) and CO₂ are amon

Question 5

Bacteria synthesize ribose for nucleotides using which pathway?

Accepted Answer

A)  Embden-Meyerhof-Parnas 
B)  Entner-Doudoroff 
C)  pentose phosphate shunt 
D)  tricarboxylic acid cycle 
E)  electron transport system 
A)  Embden-Meyerhof-Parnas 
B)  Entner-Doudoroff 
C)  pentose phosphate shunt 
D)  tricarboxylic acid cycle 
E)  electron transport system

Question 6

Each of the following was used to elucidate the TCA cycle EXCEPT

Accepted Answer

A)  using radiolabeled acetate to determine which carbons were oxidized to CO2 . 
B)  the use of crude enzyme preparations from a variety of sources such as cucumber seeds and beef liver. 
C)  adding a variety of short-chain fatty acids commonly found in cells to detect activity. 
D)  the use of C14-labeled carbon compounds as a source of carbon under anoxic conditions. 
E)  using C13 to determine which intermediates are enriched under various growth conditions. 
A)  using radiolabeled acetate to determine which carbons were oxidized to CO2 . 
B)  the use of crude enzyme preparations from a variety of sources such as cucumber seeds and beef liver. 
C)  adding a variety of short-chain fatty acids commonly found in cells to detect activity. 
D)  the use of C14-labeled carbon compounds as a source of carbon under anoxic conditions. 
E)  using C13 to determine which intermediates are enriched under various growth conditions.

Question 7

What are the differences among DG, DG°, and DG°'?

Accepted Answer

@#LAT-DLM&G is the change in Gibbs free energy for

Question 8

Which of the following is FALSE with respect to enzymes that use the reducing equivalents NADH and NADPH?

Accepted Answer

A)  Some enzymes only use NADH. 
B)  Some enzymes only use NADPH. 
C)  Some enzymes may use either NADPH or NADH. 
D)  FADH2 can be used as a substitute. 
E)  NADPH is more often used in biosynthesis. 
A)  Some enzymes only use NADH. 
B)  Some enzymes only use NADPH. 
C)  Some enzymes may use either NADPH or NADH. 
D)  FADH2 can be used as a substitute. 
E)  NADPH is more often used in biosynthesis.

Question 9

What is the phosphotransferase system (PTS) and why is the advantage for a microbial cell to have a PTS?

Accepted Answer

The PTS consists of several enzymes that

Question 10

Which of the following is NOT correct with respect to the redox pair NAD⁺/NADH?

Accepted Answer

A)  The nicotinamide ring is a relatively stable aromatic structure. 
B)  The nicotinamide ring is a heteroaromatic because it has a noncarbon atom in position 4. 
C)  The nicotinamide ring may accept two electrons at carbon 1, becoming a nonaromatic ring. 
D)  The reduced, nonaromatic ring of NADH is at a higher energy than the aromatic ring of NAD+. 
E)  NADH can accept electrons from an electron transport system. 
A)  The nicotinamide ring is a relatively stable aromatic structure. 
B)  The nicotinamide ring is a heteroaromatic because it has a noncarbon atom in position 4. 
C)  The nicotinamide ring may accept two electrons at carbon 1, becoming a nonaromatic ring. 
D)  The reduced, nonaromatic ring of NADH is at a higher energy than the aromatic ring of NAD+. 
E)  NADH can accept electrons from an electron transport system.

Question 11

Describe the diagnostic use of sorbitol MacConkey agar to test for the presence of E. coli O157:H7.

Accepted Answer

The sugar source in this medium is sorbi

Question 12

The energy yield from fermentation is lower than from respiration because

Accepted Answer

A)  fermentation uses NAD+, not NADP+. 
B)  respiration completely oxidizes glucose to CO2, resulting in greater generation of NADH and thus ATP. 
C)  respiration uses the TCA cycle, which has many steps that directly produce ATP or GTP. 
D)  fermentation shunts much of the carbon from glucose to biosynthesis. 
E)  fermentation relies on the glyoxylate bypass, which bypasses ATP production. 
A)  fermentation uses NAD+, not NADP+. 
B)  respiration completely oxidizes glucose to CO2, resulting in greater generation of NADH and thus ATP. 
C)  respiration uses the TCA cycle, which has many steps that directly produce ATP or GTP. 
D)  fermentation shunts much of the carbon from glucose to biosynthesis. 
E)  fermentation relies on the glyoxylate bypass, which bypasses ATP production.

Question 13

The flavor and other properties of cheeses derive from the type of fermenting microorganisms used. How do the "eyes" and the characteristic flavor of Swiss cheese originate?

Accepted Answer

Fermentation of milk sugars by Propionib

Question 14

Soils and waters become contaminated with industrial aromatic compounds and efforts are made to use bacteria to clean up these areas. Describe the experiment and finding from phenanthrene metabolism in the Antarctic.

Accepted Answer

Soils from the Antarctic were incubated

Question 15

Pathways involving both anabolic and catabolic reactions are referred to as

Accepted Answer

A)  amphibolic. 
B)  amphipathic. 
C)  ambivalent. 
D)  ambidextrous. 
E)  syntrophibolic. 
A)  amphibolic. 
B)  amphipathic. 
C)  ambivalent. 
D)  ambidextrous. 
E)  syntrophibolic.

Question 16

A bacterium capable of producing methane and water from carbon dioxide and hydrogen performs a type of metabolism called ________ and, given its sources of electrons, it is a ________.

Accepted Answer

A)  methanogenesis; chemolithotroph 
B)  respiration; heterotroph 
C)  fermentation; chemoorganotroph 
D)  carbon fixation; phototroph 
E)  sulfur bacterium; chemolithotroph 
A)  methanogenesis; chemolithotroph 
B)  respiration; heterotroph 
C)  fermentation; chemoorganotroph 
D)  carbon fixation; phototroph 
E)  sulfur bacterium; chemolithotroph

Question 17

The molecule shown below carries energy in the cell but it needs to be stabilized. It is a ________ molecule and is stabilized when it ________.

Accepted Answer

A)  NADPH; forms a cyclic molecule 
B)  NADPH; complexes with Mg2+ 
C)  ATP; donates its electrons to a cytochrome 
D)  ATP; complexes with Mg2+ 
E)  ATP; forms a cyclic molecule 
A)  NADPH; forms a cyclic molecule 
B)  NADPH; complexes with Mg2+ 
C)  ATP; donates its electrons to a cytochrome 
D)  ATP; complexes with Mg2+ 
E)  ATP; forms a cyclic molecule

Question 18

Which of the following statements is NOT true regarding the electron donors in prokaryotic metabolism?

Accepted Answer

A)  The use of organic compounds as electron donors is known as organotrophy. 
B)  Chemolithotrophy refers to the use of inorganic molecules as electron sources. 
C)  Photolysis of water provides electrons to phototrophic organisms such as cyanobacteria. 
D)  Electrons can be obtained from inorganic chemicals such as H2S. 
E)  Oxygen can serve as an electron donor. 
A)  The use of organic compounds as electron donors is known as organotrophy. 
B)  Chemolithotrophy refers to the use of inorganic molecules as electron sources. 
C)  Photolysis of water provides electrons to phototrophic organisms such as cyanobacteria. 
D)  Electrons can be obtained from inorganic chemicals such as H2S. 
E)  Oxygen can serve as an electron donor.

Question 19

________ enters the tricarboxylic acid cycle by condensing with oxaloacetate to form ________.

Accepted Answer

A)  Succinoyl-S-CoA; fumarate 
B)  Acetyl-S-CoA; citrate 
C)  Pyruvate; citrate 
D)  Citrate; isocitrate 
E)  Acetyl phosphate; citrate 
A)  Succinoyl-S-CoA; fumarate 
B)  Acetyl-S-CoA; citrate 
C)  Pyruvate; citrate 
D)  Citrate; isocitrate 
E)  Acetyl phosphate; citrate

Question 20

The Gibbs equation describes the relationship between the components of free energy change and can be generally expressed as

Accepted Answer

A)  $$\Delta$$G = $$\Delta$$G° + RT ln Keq. 
B)  $$\Delta$$G = $$\Delta$$H - T$$\Delta$$S. 
C)  ADP + Pi $$\leftrightarrows$$ ATP + H2O. 
D)  K = T°C + 273. 
E)  $$\Delta$$G = -2.303 RT log [C] [D] / [A] [B]. 
A)  $$\Delta$$G = $$\Delta$$G° + RT ln Keq. 
B)  $$\Delta$$G = $$\Delta$$H - T$$\Delta$$S. 
C)  ADP + Pi $$\leftrightarrows$$ ATP + H2O. 
D)  K = T°C + 273. 
E)  $$\Delta$$G = -2.303 RT log [C] [D] / [A] [B].

Exam 13: Energetics and Catabolism

What is mixed-acid fermentation? Provide examples of industrial uses of its products.

All nucleotide triphosphates carry energy. Provide examples of reactions that are driven by the release of energy from GTP, CTP, and TTP.

The laws of thermodynamics indicate that systems tend to become less ordered and that ________, a measure of disorder or randomness of the universe, always increases.

Escherichia coli degrades human waste in the colon using mixed-acid fermentation. Why is this a factor of concern in some medical procedures, such as colonoscopy?

Bacteria synthesize ribose for nucleotides using which pathway?

Each of the following was used to elucidate the TCA cycle EXCEPT

What are the differences among DG, DG°, and DG°'?

Which of the following is FALSE with respect to enzymes that use the reducing equivalents NADH and NADPH?

What is the phosphotransferase system (PTS) and why is the advantage for a microbial cell to have a PTS?

Which of the following is NOT correct with respect to the redox pair NAD⁺/NADH?

Describe the diagnostic use of sorbitol MacConkey agar to test for the presence of E. coli O157:H7.

The energy yield from fermentation is lower than from respiration because

The flavor and other properties of cheeses derive from the type of fermenting microorganisms used. How do the "eyes" and the characteristic flavor of Swiss cheese originate?

Soils and waters become contaminated with industrial aromatic compounds and efforts are made to use bacteria to clean up these areas. Describe the experiment and finding from phenanthrene metabolism in the Antarctic.

Pathways involving both anabolic and catabolic reactions are referred to as

A bacterium capable of producing methane and water from carbon dioxide and hydrogen performs a type of metabolism called ________ and, given its sources of electrons, it is a ________.

The molecule shown below carries energy in the cell but it needs to be stabilized. It is a ________ molecule and is stabilized when it ________.

Which of the following statements is NOT true regarding the electron donors in prokaryotic metabolism?

________ enters the tricarboxylic acid cycle by condensing with oxaloacetate to form ________.

The Gibbs equation describes the relationship between the components of free energy change and can be generally expressed as

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

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

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

A bacterium capable of producing methane and water from carbon dioxide and hydrogen performs a type of metabolism called and, given its sources of electrons, it is a .

The molecule shown below carries energy in the cell but it needs to be stabilized. It is a molecule and is stabilized when it .

enters the tricarboxylic acid cycle by condensing with oxaloacetate to form .