Question 1

When the nontemplate strand of a gene is transcribed into RNA, what is likely to result?

Accepted Answer

A)  A complementary sRNA will bind to it and form a functional ribozyme with secondary structure. 
B)  It will complementarily bind to the gene sequence, form a hairpin loop, and transcriptionally repress the gene. 
C)  The complementary mRNA transcribed from the template strand will bind to it and halt its translation. 
D)  A global regulator will identify this as a stress, respond by inducing ribonuclease production, and it will be degraded. 
A)  A complementary sRNA will bind to it and form a functional ribozyme with secondary structure. 
B)  It will complementarily bind to the gene sequence, form a hairpin loop, and transcriptionally repress the gene. 
C)  The complementary mRNA transcribed from the template strand will bind to it and halt its translation. 
D)  A global regulator will identify this as a stress, respond by inducing ribonuclease production, and it will be degraded.

Question 2

Multiple mechanisms for small RNA (sRNA)-mediated translational regulation exist, but all are unified by inactivating protein synthesis of the target mRNA.

Accepted Answer

A) True 
 B)False

Question 3

Explain the function of cAMP in catabolite repression.

Accepted Answer

Adenylate cyclase synthesizes the regula

Question 4

How is the activity of a riboswitch controlled?

Accepted Answer

A)  by other riboswitches 
B)  metabolite binding can change its structure 
C)  sigma factor binding alters its structure 
D)  small RNA complementary binding disrupts its function 
A)  by other riboswitches 
B)  metabolite binding can change its structure 
C)  sigma factor binding alters its structure 
D)  small RNA complementary binding disrupts its function

Question 5

Considering the catabolite repression mechanism, which observation would make you suspect it IS occurring?

Accepted Answer

A)  CRP bound to promoter sites 
B)  elevated levels of transcripts for maltose and sucrose catabolism 
C)  relatively low intracellular cyclic AMP levels 
D)  RNA polymerase bound to biosynthetic promoter sequences 
A)  CRP bound to promoter sites 
B)  elevated levels of transcripts for maltose and sucrose catabolism 
C)  relatively low intracellular cyclic AMP levels 
D)  RNA polymerase bound to biosynthetic promoter sequences

Question 6

In Bacteria, sensor kinases that respond to extracellular signals transfer this signal to the cytoplasmic machinery by typically phosphorylating the residues.

Accepted Answer

A)  histidine 
B)  serine 
C)  threonine 
D)  tyrosine 
A)  histidine 
B)  serine 
C)  threonine 
D)  tyrosine

Question 7

Phosphorylation of ________ regulates which direction a flagellum rotates, thus controlling whether an organism runs or tumbles.

Accepted Answer

A)  CheAW 
B)  CheB 
C)  CheY 
D)  CheZ 
A)  CheAW 
B)  CheB 
C)  CheY 
D)  CheZ

Question 8

Proteins and RNA molecules that are needed in the cell at about the same level under all growth conditions, require constitutive expression.

Accepted Answer

A) True 
 B)False

Question 9

In many environments, the limiting nutrient for bacterial growth is phosphorus.

Accepted Answer

A) True 
 B)False

Question 10

Attenuation is a type of regulation that can control

Accepted Answer

A)  allosteric enzyme activity. 
B)  transcriptional activity exclusively. 
C)  translational activity exclusively. 
D)  both transcriptional and translational activity. 
A)  allosteric enzyme activity. 
B)  transcriptional activity exclusively. 
C)  translational activity exclusively. 
D)  both transcriptional and translational activity.

Question 11

Proteins required at approximately the same level throughout a cellʹs growth cycle are often not subject to regulatory mechanisms and are constitutively synthesized.

Accepted Answer

A) True 
 B)False

Question 12

What are sigma factors? Explain the roles of the two different sigma factors known as RpoH and RpoS.

Accepted Answer

A sigma factor (σ factor) is a protein n

Question 13

Using the tryptophan operon as a model, describe the formation of a stem-loop structure and its function.

Accepted Answer

A pause in mRNA transcription occurs whe

Question 14

Small molecules usually act directly (rather than indirectly) in regulating transcription.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following is a characteristic of an isoenzyme?

Accepted Answer

A)  More than one enzyme is regulated by the same mechanism. 
B)  The same reaction can be catalyzed by multiple enzyme variants. 
C)  Multiple binding sites on the same enzyme enable multiple regulation mechanisms. 
D)  More than one gene makes the same enzyme. 
A)  More than one enzyme is regulated by the same mechanism. 
B)  The same reaction can be catalyzed by multiple enzyme variants. 
C)  Multiple binding sites on the same enzyme enable multiple regulation mechanisms. 
D)  More than one gene makes the same enzyme.

Question 16

Which type of regulator(s) specifically binds to operator regions of DNA?

Accepted Answer

A)  activators 
B)  activators and inducers 
C)  repressors 
D)  repressors and corepressors 
A)  activators 
B)  activators and inducers 
C)  repressors 
D)  repressors and corepressors

Question 17

The function of a kinase is

Accepted Answer

A)  methylation. 
B)  response regulation. 
C)  phosphorylation. 
D)  glycosylation. 
A)  methylation. 
B)  response regulation. 
C)  phosphorylation. 
D)  glycosylation.

Question 18

The promoters of positively controlled operons require activator proteins because

Accepted Answer

A)  RNA polymerase easily recognizes the consensus sequence. 
B)  they are required to inactivate the repressor proteins. 
C)  the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter. 
D)  they are needed to bind to the allosteric site of RNA polymerase. 
A)  RNA polymerase easily recognizes the consensus sequence. 
B)  they are required to inactivate the repressor proteins. 
C)  the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter. 
D)  they are needed to bind to the allosteric site of RNA polymerase.

Question 19

Provide evidence that supports the hypothesis that riboswitches are remnants of the RNA world when catalytic RNAs were the only self-replicating life forms.

Accepted Answer

Answers will vary, but one focus could b

Question 20

Regulation of transcription in Archaea is more similar to that which occurs in eukaryotes than in bacteria.

Accepted Answer

A) True 
 B)False

Exam 6: Microbial Regulatory Systems

When the nontemplate strand of a gene is transcribed into RNA, what is likely to result?

Multiple mechanisms for small RNA (sRNA)-mediated translational regulation exist, but all are unified by inactivating protein synthesis of the target mRNA.

Explain the function of cAMP in catabolite repression.

How is the activity of a riboswitch controlled?

Considering the catabolite repression mechanism, which observation would make you suspect it IS occurring?

In Bacteria, sensor kinases that respond to extracellular signals transfer this signal to the cytoplasmic machinery by typically phosphorylating the residues.

Phosphorylation of ________ regulates which direction a flagellum rotates, thus controlling whether an organism runs or tumbles.

Proteins and RNA molecules that are needed in the cell at about the same level under all growth conditions, require constitutive expression.

In many environments, the limiting nutrient for bacterial growth is phosphorus.

Attenuation is a type of regulation that can control

Proteins required at approximately the same level throughout a cellʹs growth cycle are often not subject to regulatory mechanisms and are constitutively synthesized.

What are sigma factors? Explain the roles of the two different sigma factors known as RpoH and RpoS.

Using the tryptophan operon as a model, describe the formation of a stem-loop structure and its function.

Small molecules usually act directly (rather than indirectly) in regulating transcription.

Which of the following is a characteristic of an isoenzyme?

Which type of regulator(s) specifically binds to operator regions of DNA?

The function of a kinase is

The promoters of positively controlled operons require activator proteins because

Provide evidence that supports the hypothesis that riboswitches are remnants of the RNA world when catalytic RNAs were the only self-replicating life forms.

Regulation of transcription in Archaea is more similar to that which occurs in eukaryotes than in bacteria.

The Microbial World

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Information Flow and Protein Processing

Microbial Growth and Its Control

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

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