Question 1

Which type of regulatory protein(s)is/are present in Archaea?

Accepted Answer

A)  Activators that stimulate RNA polymerase activity are present in Archaea. 
B)  Repressors that block RNA polymerase activity are present in Archaea. 
C)  Both activators and repressors are present in Archaea. 
D)  Similar to regulation in Eukarya, Archaea lack bacterial-like regulators such as activators and repressors and use transcription factors instead. 
A)  Activators that stimulate RNA polymerase activity are present in Archaea. 
B)  Repressors that block RNA polymerase activity are present in Archaea. 
C)  Both activators and repressors are present in Archaea. 
D)  Similar to regulation in Eukarya, Archaea lack bacterial-like regulators such as activators and repressors and use transcription factors instead.

Question 2

Considering the catabolite repression mechanism,which observation would make you suspect it is NOT 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 3

Quorum sensing generally follows the mechanism of which type of regulation?

Accepted Answer

A)  feedback inhibition 
B)  negative transcriptional regulation 
C)  positive transcriptional regulation 
D)  two-component regulation system 
A)  feedback inhibition 
B)  negative transcriptional regulation 
C)  positive transcriptional regulation 
D)  two-component regulation system

Question 4

Which of the following do NOT bind to the promoter sequence during regulation?

Accepted Answer

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

Question 5

Which enzyme would be BEST to include in a protein extract to refold and denature improperly folded proteins?

Accepted Answer

A)  DnaK 
B)  RepA 
C)  RpoH 
D)  Spo0A 
A)  DnaK 
B)  RepA 
C)  RpoH 
D)  Spo0A

Question 6

Using the tryptophan operon as a model,explain a transcription pause site and the formation of a stem-loop.

Accepted Answer

A pause in mRNA transcription occurs whe

Question 7

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

Accepted Answer

A) True 
 B)False

Question 8

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 9

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 10

The most frequent way in which regulatory RNA molecules exert their effects is by

Accepted Answer

A)  base pairing with other RNA molecules that have regions of complementary sequence. 
B)  binding to a repressor and repressing enzyme transcription. 
C)  acting as an inducer that then binds to an activator protein to allow transcription to proceed. 
D)  signal transduction. 
A)  base pairing with other RNA molecules that have regions of complementary sequence. 
B)  binding to a repressor and repressing enzyme transcription. 
C)  acting as an inducer that then binds to an activator protein to allow transcription to proceed. 
D)  signal transduction.

Question 11

Explain the phenomenon known as diauxic growth.Hypothesize why this type of regulation might be important for survival of a microbe in a community as well as a situation where lacking it might be advantageous.

Accepted Answer

As an example,Escherichia coli exposed t

Question 12

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 13

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 complementary bind to the gene sequence, form a hairpin loop, and transcriptionally repress the gene. 
C)  The complementary mRNA also 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 degraded. 
A)  A complementary sRNA will bind to it and form a functional ribozyme with secondary structure. 
B)  It will complementary bind to the gene sequence, form a hairpin loop, and transcriptionally repress the gene. 
C)  The complementary mRNA also 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 degraded.

Question 14

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 15

When arginine is added to a culture 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 16

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 have nucleotide sequences that bind RNA polymerase weakly, which are not close matches to the consensus sequence. 
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 have nucleotide sequences that bind RNA polymerase weakly, which are not close matches to the consensus sequence. 
D)  they are needed to bind to the allosteric site of RNA polymerase.

Question 17

Transcriptional regulation is considered negative when an inducer binds to and deactivates a repressor.

Accepted Answer

A) True 
 B)False

Question 18

Once cytoplasmic sensor proteins involved in chemotaxis regulation are phosphorylated,a cascade of other phosphate-transferring mechanisms provide ATP energy to rotate flagella.

Accepted Answer

A) True 
 B)False

Question 19

Explain the translational attenuation mechanism.

Accepted Answer

Attenuation is a mechanism that controls

Question 20

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.

Exam 7: Metabolic Regulation

Which type of regulatory protein(s)is/are present in Archaea?

Considering the catabolite repression mechanism,which observation would make you suspect it is NOT occurring?

Quorum sensing generally follows the mechanism of which type of regulation?

Which of the following do NOT bind to the promoter sequence during regulation?

Which enzyme would be BEST to include in a protein extract to refold and denature improperly folded proteins?

Using the tryptophan operon as a model,explain a transcription pause site and the formation of a stem-loop.

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

Attenuation is a type of regulation that can control

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

The most frequent way in which regulatory RNA molecules exert their effects is by

Explain the phenomenon known as diauxic growth.Hypothesize why this type of regulation might be important for survival of a microbe in a community as well as a situation where lacking it might be advantageous.

How is the activity of a riboswitch controlled?

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

The function of a kinase is

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

The promoters of positively controlled operons require activator proteins,because

Transcriptional regulation is considered negative when an inducer binds to and deactivates a repressor.

Once cytoplasmic sensor proteins involved in chemotaxis regulation are phosphorylated,a cascade of other phosphate-transferring mechanisms provide ATP energy to rotate flagella.

Explain the translational attenuation mechanism.

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

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