Question 1

Which metabolic cycle or pathway is LEAST likely to be invoked during the biosynthesis of DNA?

Accepted Answer

A)  citric acid cycle 
B)  glycolysis 
C)  gluconeogenesis 
D)  pentose phosphate pathway 
A)  citric acid cycle 
B)  glycolysis 
C)  gluconeogenesis 
D)  pentose phosphate pathway

Question 2

If a substance is reduced, it gains electrons.

Accepted Answer

A) True 
 B)False

Question 3

When culturing a chemoorganoheterophic bacterium, what outcome is LEAST likely to occur if ammonia and phosphate are provided at equal concentrations?

Accepted Answer

A)  Cells require much less P to grow than N, so extra P will be used for ATP synthesis and result in a faster growth rate. 
B)  Cells will never consume all of the phosphate, because N is needed in higher quantities than P. 
C)  The final biomass of cells will be no different than if only 50% of the phosphate was provided. 
D)  The bacteria will import all of the ammonia to use for biosynthetic pathways. 
A)  Cells require much less P to grow than N, so extra P will be used for ATP synthesis and result in a faster growth rate. 
B)  Cells will never consume all of the phosphate, because N is needed in higher quantities than P. 
C)  The final biomass of cells will be no different than if only 50% of the phosphate was provided. 
D)  The bacteria will import all of the ammonia to use for biosynthetic pathways.

Question 4

Magnesium is not considered a growth factor for microorganisms, because growth factors are always organic compounds.

Accepted Answer

A) True 
 B)False

Question 5

Catabolic pathways are essential for microorganisms to obtain energy, because biosynthetic reactions for cellular growth generally require energy input.

Accepted Answer

A) True 
 B)False

Question 6

The change in Gibbs free energy for a particular reaction is most useful in determining

Accepted Answer

A)  the amount of energy catalysts required for biosynthesis or catabolism. 
B)  the potential metabolic reaction rate. 
C)  whether there will be a requirement or production of energy. 
D)  energy stored in each compound. 
A)  the amount of energy catalysts required for biosynthesis or catabolism. 
B)  the potential metabolic reaction rate. 
C)  whether there will be a requirement or production of energy. 
D)  energy stored in each compound.

Question 7

Compare and contrast defined media and complex media. Use specific examples in your answer.

Accepted Answer

Defined media are prepared by adding ind

Question 8

Fermentation has a relatively low ATP yield compared to aerobic respiration because

Accepted Answer

A)  more reducing equivalents are used for anaerobic catabolism. 
B)  less ATP is consumed during the first stage of aerobic catabolism. 
C)  oxidative phosphorylation yields a lot of ATP. 
D)  substrate-level phosphorylation yields a lot of ATP. 
A)  more reducing equivalents are used for anaerobic catabolism. 
B)  less ATP is consumed during the first stage of aerobic catabolism. 
C)  oxidative phosphorylation yields a lot of ATP. 
D)  substrate-level phosphorylation yields a lot of ATP.

Question 9

Which intermediate compound(s) in the citric acid cycle is/are often used for biosynthetic pathways as well as carbon catabolism?

Accepted Answer

A)  only α-ketoglutarate 
B)  only oxaloacetate 
C)  only succinyl-CoA 
D)  α-ketoglutarate, oxaloacetate, and succinyl-CoA 
A)  only α-ketoglutarate 
B)  only oxaloacetate 
C)  only succinyl-CoA 
D)  α-ketoglutarate, oxaloacetate, and succinyl-CoA

Question 10

Nitrogenases not only reduce N₂ but also can act on acetylene (C₂H₂).

Accepted Answer

A) True 
 B)False

Question 11

In aerobic respiration, the final electron acceptor is

Accepted Answer

A)  hydrogen. 
B)  oxygen. 
C)  water. 
D)  ATP. 
A)  hydrogen. 
B)  oxygen. 
C)  water. 
D)  ATP.

Question 12

The net result of electron transport is the generation of a pH gradient and an electrochemical potential across the membrane.

Accepted Answer

A) True 
 B)False

Question 13

To ensure growth of a newly discovered bacterium with unknown nutritional requirements, it would be best to begin with a ________ medium rather than a ________ medium.

Accepted Answer

A)  complex / minimal 
B)  minimal / complex 
C)  selective / complex 
D)  selective / differential 
A)  complex / minimal 
B)  minimal / complex 
C)  selective / complex 
D)  selective / differential

Question 14

All of the following are non-protein electron carriers EXCEPT

Accepted Answer

A)  FADH₂. 
B)  FMNH₂. 
C)  cytochromes. 
D)  quinones. 
A)  FADH₂. 
B)  FMNH₂. 
C)  cytochromes. 
D)  quinones.

Question 15

In an aquatic microbial community where a photoautotroph, chemoorganoheterotroph, and nitrogen fixing bacterium are present, predict an environmental perturbation that would cause only one to be outcompeted by the other two groups and explain how each group would respond.

Accepted Answer

Answers will vary but should highlight a

Question 16

Which two metabolic processes are most dissimilar?

Accepted Answer

A)  citric acid cycle and glycolysis 
B)  glycolysis and gluconeogenesis 
C)  proton motive force and substrate-level phosphorylation 
D)  pentose phosphate pathway and glycolysis 
A)  citric acid cycle and glycolysis 
B)  glycolysis and gluconeogenesis 
C)  proton motive force and substrate-level phosphorylation 
D)  pentose phosphate pathway and glycolysis

Question 17

Which of the following statements is FALSE?

Accepted Answer

A)  Most bacteria are capable of using ammonia as their sole nitrogen source. 
B)  Some bacteria are able to use nitrates or nitrogen gas as their nitrogen source. 
C)  Most available nitrogen is in organic forms. 
D)  Nitrogen is a major component of proteins and nucleic acids. 
A)  Most bacteria are capable of using ammonia as their sole nitrogen source. 
B)  Some bacteria are able to use nitrates or nitrogen gas as their nitrogen source. 
C)  Most available nitrogen is in organic forms. 
D)  Nitrogen is a major component of proteins and nucleic acids.

Question 18

Depending on the particular metabolism of a bacterium, electron transport can be used to energize and rotate ATP synthase.

Accepted Answer

A) True 
 B)False

Question 19

Varied coenzyme availability increases the diversity of enzymatic reactions in both biosynthetic and catabolic pathways possible in a cell.

Accepted Answer

A) True 
 B)False

Question 20

Explain why the amount of energy released in a redox reaction depends on the nature of both the electron donor and the electron acceptor.

Accepted Answer

Answers should emphasize that energy doe

Exam 3: Microbial Metabolism

Which metabolic cycle or pathway is LEAST likely to be invoked during the biosynthesis of DNA?

If a substance is reduced, it gains electrons.

When culturing a chemoorganoheterophic bacterium, what outcome is LEAST likely to occur if ammonia and phosphate are provided at equal concentrations?

Magnesium is not considered a growth factor for microorganisms, because growth factors are always organic compounds.

Catabolic pathways are essential for microorganisms to obtain energy, because biosynthetic reactions for cellular growth generally require energy input.

The change in Gibbs free energy for a particular reaction is most useful in determining

Compare and contrast defined media and complex media. Use specific examples in your answer.

Fermentation has a relatively low ATP yield compared to aerobic respiration because

Which intermediate compound(s) in the citric acid cycle is/are often used for biosynthetic pathways as well as carbon catabolism?

Nitrogenases not only reduce N₂ but also can act on acetylene (C₂H₂).

In aerobic respiration, the final electron acceptor is

The net result of electron transport is the generation of a pH gradient and an electrochemical potential across the membrane.

To ensure growth of a newly discovered bacterium with unknown nutritional requirements, it would be best to begin with a ________ medium rather than a ________ medium.

All of the following are non-protein electron carriers EXCEPT

In an aquatic microbial community where a photoautotroph, chemoorganoheterotroph, and nitrogen fixing bacterium are present, predict an environmental perturbation that would cause only one to be outcompeted by the other two groups and explain how each group would respond.

Which two metabolic processes are most dissimilar?

Which of the following statements is FALSE?

Depending on the particular metabolism of a bacterium, electron transport can be used to energize and rotate ATP synthase.

Varied coenzyme availability increases the diversity of enzymatic reactions in both biosynthetic and catabolic pathways possible in a cell.

Explain why the amount of energy released in a redox reaction depends on the nature of both the electron donor and the electron acceptor.

The Microbial World

Microbial Cell Structure and Function

Molecular Information Flow and Protein Processing

Microbial Growth and Its Control

Microbial Regulatory Systems

Molecular Biology of Microbial Growth

Viruses and Their Replication

Microbial Systems Biology

Viral Genomics, Diversity, and Ecology

Genetics of Bacteria and Archaea

Biotechnology and Synthetic Biology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Microorganisms

Diversity of Bacteria

Diversity of Archaea

Diversity of Microbial Eukarya

Taking the Measure of Microbial Systems

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Symbioses with Humans

Microbial Infection and Pathogenesis

Innate Immunity: Broadly Specific Host Defenses

Adaptive Immunity: Highly Specific Host Defenses

Clinical Microbiology and Immunology

Epidemiology

Person-to-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Waterborne and Foodborne Bacterial and Viral Diseases

Eukaryotic Pathogens: Fungi, Protozoans, and Helminths

Filters

To ensure growth of a newly discovered bacterium with unknown nutritional requirements, it would be best to begin with a medium rather than a medium.