Question 1

Transcriptional regulators bind most frequently at the ________ site of DNA.

Accepted Answer

A)  major groove 
B)  minor groove 
C)  histone complex 
D)  primary supercoil 
A)  major groove 
B)  minor groove 
C)  histone complex 
D)  primary supercoil

Question 2

Explain why is it unsurprising that two-component regulatory systems are all but absent in bacteria that live at the expense of a host.

Accepted Answer

Answers will vary, but a possible explan

Question 3

In negative control of transcription by the lac operon, how does the presence of an inducer affect transcription?

Accepted Answer

A)  The inducer binds to the operator. 
B)  The inducer does not bind to the operator. 
C)  The inducer causes the repressor to bind to the operator. 
D)  The inducer prevents the repressor from binding to the operator. 
A)  The inducer binds to the operator. 
B)  The inducer does not bind to the operator. 
C)  The inducer causes the repressor to bind to the operator. 
D)  The inducer prevents the repressor from binding to the operator.

Question 4

Describe the basic two-component regulatory system, and explain the function of each component.

Accepted Answer

The first component of the system involv

Question 5

In order for the helix-turn-helix motif to bind to DNA, the ________ must fit into the major groove of the DNA.

Accepted Answer

A)  homeotic switches 
B)  recognition helix 
C)  operator 
D)  zinc fingers 
A)  homeotic switches 
B)  recognition helix 
C)  operator 
D)  zinc fingers

Question 6

Explain how adaptation of the chemotaxis system is achieved once an organism has responded to a stimulus.

Accepted Answer

Once an organism has successfully respon

Question 7

Regulatory proteins

Accepted Answer

A)  are influenced by small molecules. 
B)  bind to specific DNA sites. 
C)  regulate transcription. 
D)  regulate transcription, bind specific DNA sites, and can be influenced by small molecules. 
A)  are influenced by small molecules. 
B)  bind to specific DNA sites. 
C)  regulate transcription. 
D)  regulate transcription, bind specific DNA sites, and can be influenced by small molecules.

Question 8

When arginine is added to a culture already growing exponentially in a medium without arginine, what occurs?

Accepted Answer

A)  All cellular growth ceases. 
B)  Growth continues, but the production of enzymes required for the synthesis of arginine ceases. 
C)  Growth continues, but the production of enzymes required for the synthesis of arginine increases. 
D)  The cell returns to the lag stage of growth to synthesize the proteins necessary for the metabolism of arginine. 
A)  All cellular growth ceases. 
B)  Growth continues, but the production of enzymes required for the synthesis of arginine ceases. 
C)  Growth continues, but the production of enzymes required for the synthesis of arginine increases. 
D)  The cell returns to the lag stage of growth to synthesize the proteins necessary for the metabolism of arginine.

Question 9

Depending on the type of regulatory mechanism, activators and repressors can bind to operator regions which control transcription.

Accepted Answer

A) True 
 B)False

Question 10

In most cases, the first product of a particular biosynthetic pathway represses the enzymes of the pathway.

Accepted Answer

A) True 
 B)False

Question 11

________ pathways typically rely on ________ proteins to inhibit mRNA synthesis.

Accepted Answer

A)  Anabolic; repressor 
B)  Catabolic; repressor 
C)  Anabolic; activator 
D)  Catabolic; activator 
A)  Anabolic; repressor 
B)  Catabolic; repressor 
C)  Anabolic; activator 
D)  Catabolic; activator

Question 12

The small size of prokaryotic cells limits their ability to respond to spatial gradients of a chemical.

Accepted Answer

A) True 
 B)False

Question 13

Contrast prokaryotic and eukaryotic regulation of gene expression.

Accepted Answer

In Bacteria and Archaea, a common mechan

Question 14

Which statement is TRUE of two separate regulators controlling one individual operon?

Accepted Answer

A)  The two regulators themselves must respond to different signals, which enables both to control the operon differently. 
B)  One regulator will likely control the transcription of one section of the operon, whereas the other regulator will control the other component. 
C)  One regulator will bind to the operator region whereas the other will bind to the promoter region so they can co-occur and co-regulate the operon. 
D)  Two regulators trying to control the same operon will likely result in only one being maintained after several generations. 
A)  The two regulators themselves must respond to different signals, which enables both to control the operon differently. 
B)  One regulator will likely control the transcription of one section of the operon, whereas the other regulator will control the other component. 
C)  One regulator will bind to the operator region whereas the other will bind to the promoter region so they can co-occur and co-regulate the operon. 
D)  Two regulators trying to control the same operon will likely result in only one being maintained after several generations.

Question 15

What occurs when an inducer is added to an environment containing an organism with a metabolic pathway controlled by a repressor?

Accepted Answer

A)  The inducer combines with the repressor and activates the pathway. 
B)  The inducer combines with the repressor and inactivates the pathway. 
C)  The inducer combines with the substrate and blocks induction. 
D)  The inducer does not combine with, but functions as a chaperone molecule for, the enzyme-substrate complex. 
A)  The inducer combines with the repressor and activates the pathway. 
B)  The inducer combines with the repressor and inactivates the pathway. 
C)  The inducer combines with the substrate and blocks induction. 
D)  The inducer does not combine with, but functions as a chaperone molecule for, the enzyme-substrate complex.

Question 16

In considering the function of heat shock proteins, why is it not surprising that these proteins are both highly conserved and very ancient? Provide your reasoning.

Accepted Answer

Answers will vary, but one idea is for a

Question 17

What would be the result of a mutation that results in the inactivation of the Tar MCP in Escherichia coli?

Accepted Answer

The mechanism of chemotaxis depends upon

Question 18

Adaptation is based on the level of phosphorylation of MCPs.

Accepted Answer

A) True 
 B)False

Question 19

Heat shock proteins are produced in high number to minimize damaging effects during high heat conditions, in addition to other stress signals unrelated to heat such as ultraviolet radiation.

Accepted Answer

A) True 
 B)False

Question 20

Transcriptional control in Archaea most closely resembles that in ________ and utilizes ________.

Accepted Answer

A)  bacteria; regulatory proteins 
B)  eukaryotes; regulatory proteins 
C)  bacteria; transcription factors 
D)  eukaryotes; transcription factors 
A)  bacteria; regulatory proteins 
B)  eukaryotes; regulatory proteins 
C)  bacteria; transcription factors 
D)  eukaryotes; transcription factors

Exam 6: Microbial Regulatory Systems

Transcriptional regulators bind most frequently at the ________ site of DNA.

Explain why is it unsurprising that two-component regulatory systems are all but absent in bacteria that live at the expense of a host.

In negative control of transcription by the lac operon, how does the presence of an inducer affect transcription?

Describe the basic two-component regulatory system, and explain the function of each component.

In order for the helix-turn-helix motif to bind to DNA, the ________ must fit into the major groove of the DNA.

Explain how adaptation of the chemotaxis system is achieved once an organism has responded to a stimulus.

Regulatory proteins

When arginine is added to a culture already growing exponentially in a medium without arginine, what occurs?

Depending on the type of regulatory mechanism, activators and repressors can bind to operator regions which control transcription.

In most cases, the first product of a particular biosynthetic pathway represses the enzymes of the pathway.

________ pathways typically rely on ________ proteins to inhibit mRNA synthesis.

The small size of prokaryotic cells limits their ability to respond to spatial gradients of a chemical.

Contrast prokaryotic and eukaryotic regulation of gene expression.

Which statement is TRUE of two separate regulators controlling one individual operon?

What occurs when an inducer is added to an environment containing an organism with a metabolic pathway controlled by a repressor?

In considering the function of heat shock proteins, why is it not surprising that these proteins are both highly conserved and very ancient? Provide your reasoning.

What would be the result of a mutation that results in the inactivation of the Tar MCP in Escherichia coli?

Adaptation is based on the level of phosphorylation of MCPs.

Heat shock proteins are produced in high number to minimize damaging effects during high heat conditions, in addition to other stress signals unrelated to heat such as ultraviolet radiation.

Transcriptional control in Archaea most closely resembles that in ________ and utilizes ________.

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

Filters

pathways typically rely on proteins to inhibit mRNA synthesis.

Transcriptional control in Archaea most closely resembles that in and utilizes .