Upgrade to remove ads
Only $35.99/year

Ch 14

Terms in this set (61)

How does E. coli assess whether the level of attractant in the media is increasing or decreasing in order to modulate runs vs. tumbles?

Multiple Choice
When CheY is phosphorylated, the cell runs, indicating high levels of attractant in the media.
Every few seconds it measures the level of methylated sites on the periplasmic side of the MCPs against the level of attractant bound to MCPs in the cytoplasm.
Every few seconds the attractant level is measured by comparing the level of methylation on the cytoplasmic side of the MCPs against the level of bound attractant on the periplasmic side of the MCPs.
When attractant is high, CheA autophosphorylates and the cell runs.
Every few seconds the attractant level is measured by comparing the level of methylation on the cytoplasmic side of the MCPs against the level of bound attractant on the periplasmic side of the MCPs.
When E. coli is grown in a high osmotic pressure environment, _________.

Multiple Choice
MicF RNA is not transcribed allowing a stem-loop structure to form at the site of translation initiation
MicF RNA is not transcribed so the OmpF mRNA is readily translated to synthesize the OmpF porin protein
MicF RNA is transcribed and base pairs with the OmpF mRNA at the ribosome binding site effectively preventing translation of the OmpF porin protein
MicF RNA is transcribed and base pairs with the OmpF mRNA at the ribosome binding site and enhances translation of the OmpF porin protein
MicF RNA is transcribed and base pairs with the OmpF mRNA at the ribosome binding site effectively preventing translation of the OmpF porin protein
For many years microbial geneticists focused almost exclusively on the regulation of transcription initiation. A likely reason for this is _________.

Multiple Choice
the process of transcription in microbes was better understood than that of translation
it is easier to study proteins than RNA
it was thought that gene expression in microbes was regulated solely by proteins
examples of translational control had not been discovered in microbes
the process of transcription in microbes was better understood than that of translation
An active repressor protein _________.
Multiple Choice
binds to the RNA polymerase, preventing messenger RNA synthesis
binds to an inducer to activate
it is a structural protein
binds to the DNA molecule and prevents transcription
binds to the DNA molecule and promotes transcription initiation
binds to the DNA molecule and prevents transcription
When a microorganism such as E. coli is grown on glucose it is _________.
Multiple Choice
it is unable to produce its peptidoglycan layer
incapable of amino acid production
unable to synthesize a cell wall
unable to produce ATP
capable of amino acid production
capable of amino acid production
Transcription is turned off by _________.

Multiple Choice
induction, repression, and activation
activation
repression
induction
repression
In regulation by repression _________.
Multiple Choice
an inducer activates the activator so that it binds to DNA and prevents transcription
a sugar, such as lactose, acts as an inducer and combines with the repressor to prevent transcription
an amino acid binds to the operator, blocking the repressor, allowing transcription to proceed
an amino acid activates the repressor so that the repressor binds to the operator and prevents transcription
an amino acid activates the repressor so that the repressor binds to the operator and prevents transcription
Comparing two-component signal transduction systems and phosphorelay systems, _________.
Multiple Choice
two-component signal transduction systems mediate the transfer of a single phosphoryl group from a sensor kinase to a response regulator, whereas phosphorelay systems transfer multiple phosphoryl groups between a series of proteins
two-component signal transduction systems mediate the transfer of multiple phosphoryl groups between a variety of sensor kinases, whereas phosphorelay systems transfer a single phosphoryl group to a response regulator
the two processes differ only in that phosphorelay systems are more widespread than two-component signal transduction systems
phosphorelay systems mediate the transfer of a single phosphoryl group from a sensor kinase to a response regulator, whereas two-component signal transduction systems transfer multiple phosphoryl groups between a series of proteins
two-component signal transduction systems mediate the transfer of a single phosphoryl group from a sensor kinase to a response regulator, whereas phosphorelay systems transfer multiple phosphoryl groups between a series of proteins
If transcription and translation were not coupled in bacteria, what type of regulation would be affected?
Multiple Choice
Riboswitches
Attenuation
Negative transcriptional control of repressible genes
Negative transcriptional control of inducible genes
Attenuation
The lac operon is expressed when glucose is _________.
Multiple Choice
high and lactose is present
low and lactose is present
low and lactose is absent
high and lactose is absent
glucose is low, regardless of the presence or absence of lactose
low and lactose is present
When in a complex with ________, the CAP protein binds to the CAP site and ________ the expression of the lac operon.
Multiple Choice
cAMP; switches on
cAMP; switches off
glucose; switches on
lactose; switches on
glucose; switches off
cAMP; switches on
In the absence of lactose, the lac repressor is __________.
Multiple Choice
inactive and can bind to the operator
inactive and cannot bind to the promoter
active and can bind to the operator
inactive and cannot bind to the operator
active and cannot bind to the operator
PrevQuestion 20 of 25 Total20 of 25Visit question mapNe
active and can bind to the operator
Which of the following statements best explains why microbial geneticists initially focused on regulation of gene expression at the transcriptional, rather than the translational, level?
Multiple Choice
By regulating the first step of protein synthesis, cells conserve the greatest amount of energy.
The process of transcription was best understood by researchers at the time.
Cellular regulation of transcription is common to all prokaryotic cells.
The process of synthesizing an mRNA transcript is much less complex than translation of mRNA into protein.
By regulating the first step of protein synthesis, cells conserve the greatest amount of energy.
When does a cell regulate gene expression?
Multiple Choice
Pretranscription through posttranslation
Posttranscription through posttranslation
Pretranscription through pretranslation
Posttranscription through pretranslation
Pretranscription through posttranslation
Which statement best describes the mechanism(s) of posttranslational regulation of gene expression?
Multiple Choice
Allosteric regulation following transcription of mRNA occurs in many biosynthetic pathways.
Protein synthesis is often repressed by feedback or noncompetitive inhibition.
Covalent modification of newly synthesized proteins generally has no marked effect on protein function.
Once a protein is synthesized, there is little to no postranslational modification.
Allosteric regulation following transcription of mRNA occurs in many biosynthetic pathways.
Sets with similar terms