Question 1

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

Accepted Answer

Answers will vary,but one idea is for an

Question 2

Illustrate and explain an operon that is subject to both positive and negative control containing the operator region,the operon,the promoter,the activator binding site,and the functional genes in a DNA sequence.Also compare and contrast the roles activators and repressors have in regulating the illustrated operon.

Accepted Answer

A combination of Figure 7.8 in the textb

Question 3

During the biotransformation of a large molecular weight compound,two major products are formed.While one of the products is catabolized,the other compounds accumulation represses the biotransformation of the large compound.Which approach is MOST likely to artificially enhance the biotransformation beyond this point in a batch culture?

Accepted Answer

A)  addition of an isoenzyme for the biotransformation route to increase its transcription 
B)  addition of inducer molecules into the medium to increase transcriptional repression 
C)  inclusion of more of an intermediate compound in the catabolic pathway 
D)  spike in additional activator proteins that control the transcription of this pathway 
A)  addition of an isoenzyme for the biotransformation route to increase its transcription 
B)  addition of inducer molecules into the medium to increase transcriptional repression 
C)  inclusion of more of an intermediate compound in the catabolic pathway 
D)  spike in additional activator proteins that control the transcription of this pathway

Question 4

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 be

Question 5

Which of the following mechanisms leads to INCREASED transcriptional activity?

Accepted Answer

A)  An sRNA binds to the ribosome binding site. 
B)  Ribonuclease activity is blocked by sRNA complementary binding to the end of a transcript. 
C)  The ribosome binding site is made available from sRNA binding to part of it. 
D)  Recruitment of RNA polymerase is enhanced when sRNA binds to and removes a repressor. 
A)  An sRNA binds to the ribosome binding site. 
B)  Ribonuclease activity is blocked by sRNA complementary binding to the end of a transcript. 
C)  The ribosome binding site is made available from sRNA binding to part of it. 
D)  Recruitment of RNA polymerase is enhanced when sRNA binds to and removes a repressor.

Question 6

A repressor is a molecule that represses biosynthesis of an mRNA transcript.

Accepted Answer

A) True 
 B)False

Question 7

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 8

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

Accepted Answer

The first component of the system involv

Question 9

How would you design an sRNA to bind to a sequence?

Accepted Answer

A)  select six continuous nucleotides from the sequence 
B)  take the complementary sequence of six continuous nucleotides 
C)  select 200 continuous nucleotides from the sequence 
D)  take the complementary sequence of 200 continuous nucleotides 
A)  select six continuous nucleotides from the sequence 
B)  take the complementary sequence of six continuous nucleotides 
C)  select 200 continuous nucleotides from the sequence 
D)  take the complementary sequence of 200 continuous nucleotides

Question 10

In negative control of transcription,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 11

The preferential use of glucose over other available carbon substrates for growth is mechanistically explained by catabolite repression.

Accepted Answer

A) True 
 B)False

Question 12

What is the difference between an operator and a promoter?

Accepted Answer

A promoter sequence is found upstream of

Question 13

Explain why cellular cannibalism is beneficial for sporulating Bacillus subtilis.

Accepted Answer

A cell that undergoes sporulation in res

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

Cyclic AMP is synthesized from ATP by an enzyme called ________ which is involved in ________.

Accepted Answer

A)  adenylate cyclase / catabolite repression 
B)  adenylate cyclase / transcriptional activation 
C)  cAMP receptor protein (CRP) synthase / catabolite repression 
D)  cAMP receptor protein (CRP) synthase / transcriptional activation 
A)  adenylate cyclase / catabolite repression 
B)  adenylate cyclase / transcriptional activation 
C)  cAMP receptor protein (CRP) synthase / catabolite repression 
D)  cAMP receptor protein (CRP) synthase / transcriptional activation

Question 16

The lac operon is an example of ________ control in which the presence of an ________ is required for transcription to occur.

Accepted Answer

A)  negative / activator 
B)  negative / inducer 
C)  positive / activator 
D)  positive / inducer 
A)  negative / activator 
B)  negative / inducer 
C)  positive / activator 
D)  positive / inducer

Question 17

A regulon always includes at least two operons.

Accepted Answer

A) True 
 B)False

Question 18

Bacteria from the genus Caulobacter are used to model cellular differentiation in eukaryotes.The abundance of CtrA,DnaA,and GcrA separately control activity of other genes necessary for differentiation in Caulobacter.Thus,these three proteins can be classified as

Accepted Answer

A)  activating sensors. 
B)  heterologous regulators. 
C)  differentiating regulons. 
D)  transcriptional regulators. 
A)  activating sensors. 
B)  heterologous regulators. 
C)  differentiating regulons. 
D)  transcriptional regulators.

Question 19

During chemotaxis,attractants increase the rate of autophosphorylation whereas repellants decrease this rate.

Accepted Answer

A) True 
 B)False

Question 20

An organism grown in a high nutrient liquid broth to high turbidity always appears to produce a blue pigment and even when a large inoculum is transferred to a nutrient rich agar plate it appears blue.When the researcher noticed it never appears blue when very small colonies were grown in low nutrient agar plates.What is the most plausible conclusion?

Accepted Answer

A)  Large populations enabled the differentiation of a subpopulation of cells that created the blue pigment. 
B)  Only high nutrient conditions provide enough energy for cells to produce this secondary metabolite that appears blue. 
C)  The blue pigment production is linked to quorum sensing. 
D)  The strong gradient from very high to low nutrient bioavailability induces production of the blue metabolite. 
A)  Large populations enabled the differentiation of a subpopulation of cells that created the blue pigment. 
B)  Only high nutrient conditions provide enough energy for cells to produce this secondary metabolite that appears blue. 
C)  The blue pigment production is linked to quorum sensing. 
D)  The strong gradient from very high to low nutrient bioavailability induces production of the blue metabolite.

Exam 7: Metabolic Regulation

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

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

Which of the following mechanisms leads to INCREASED transcriptional activity?

A repressor is a molecule that represses biosynthesis of an mRNA transcript.

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

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

How would you design an sRNA to bind to a sequence?

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

The preferential use of glucose over other available carbon substrates for growth is mechanistically explained by catabolite repression.

What is the difference between an operator and a promoter?

Explain why cellular cannibalism is beneficial for sporulating Bacillus subtilis.

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

Cyclic AMP is synthesized from ATP by an enzyme called ________ which is involved in ________.

The lac operon is an example of ________ control in which the presence of an ________ is required for transcription to occur.

A regulon always includes at least two operons.

Bacteria from the genus Caulobacter are used to model cellular differentiation in eukaryotes.The abundance of CtrA,DnaA,and GcrA separately control activity of other genes necessary for differentiation in Caulobacter.Thus,these three proteins can be classified as

During chemotaxis,attractants increase the rate of autophosphorylation whereas repellants decrease this rate.

Microorganisms and Microbiology

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Biology

Microbial Growth and Control

Microbial Genomics

Viruses and Virology

Viral Genomes and Diversity

Genetics of Bacteria and Archaea

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters

Cyclic AMP is synthesized from ATP by an enzyme called which is involved in .

The lac operon is an example of control in which the presence of an is required for transcription to occur.