Chapter 14 (post)

The lac repressor is inactivated by binding to which of the following? -Lactose -Beta-galactosidase -Transcription factors -Glucose -Allolactose

-Allolactose

How can antisense RNA inhibit translation? -An antisense RNA forms a single-stranded structure that inhibits translation. -An antisense RNA binds to a translation inhibitor protein and prevents translation. -An antisense RNA makes a protein that inhibits translation. -An antisense RNA binds to a transcript and inhibits translation.

-An antisense RNA binds to a transcript and inhibits translation.

If a bacteria is placed in an environment that contains both glucose and lactose, the regulation of the lac operon will allow which nutrient to be processed first? -Glucose -Lactose -Both will be processed equally -Neither will be processed in this environment

-Glucose

A deletion in an operon removes the terminator. How will that affect the transcript that is produced from the operon? -The transcript will be produced and normal in length -The transcript will be produced, but shorter than normal -The transcript will be produced, but longer than normal -The transcript will produced, but will contain a deletion -The transcript will not be produced

-The transcript will be produced, but longer than normal

A deletion in an operon removes the promoter. How will that affect the transcript that is produced from the operon? -The transcript will be produced and normal in length -The transcript will be produced, but shorter than normal -The transcript will be produced, but longer than normal -The transcript will produced, but will contain a deletion -The transcript will not be produced

-The transcript will not be produced

Which of the following is not part of the lac operon? -lacO -lacZ -lacA -lacI -lacP

-lacI

The lac repressor binds to what site within the lac operon? -lacZ -lacO -lacA -lacl -lacP

-lacO

How many promoters are in an operon? =1 =2 =3 =It depends on how many genes are present in the operon

=1

True/False When both glucose and lactose are absent, transcription of the lac operon occurs.

False

(Transcription, Translation or Post-translation) A protein is covalently modified.

Posttranslation

(Transcription, Translation or Post-translation) The product of a metabolic pathway inhibits the first enzyme in a pathway.

Posttranslation

(Transcription, Translation or Post-translation) A transcription terminator forms in the RNA.

Transcription

(Transcription, Translation or Post-translation) Genetic regulatory proteins bind to the DNA.

Transcription

(Transcription, Translation or Post-translation) Antisense RNA binds to the mRNA.

Translation

(Transcription, Translation or Post-translation) Repressor proteins bind to an mRNA and prevent ribosome binding.

Translation

(Transcription, Translation or Post-translation) Riboswitches produce an RNA conformation that prevents ribosome binding.

Translation

True/False In the absence of glucose and presence of lactose, allolactose combines with the repressor and allows RNA polymerase to proceed with transcription.

True

True/False Polycistronic mRNA is transcribed from the lac operon when lactose is present in the cell.

True

True/False The lac repressor protein is active in the absence of lactose within the cell.

True

Which of the following sets of conditions would result in high levels of gene transcription from the lac operon? -High glucose, low lactose -High glucose, high lactose -Low glucose, low lactose -Low glucose, high lactose

-Low glucose, high lactose

Which of the following is an example of post translational regulation in prokaryotes? -Sterically blocking the ribosome -Phosphorylation of an enzyme -Incorporation of antisense RNA -Altering the structure of the mRNA

-Phosphorylation of an enzyme

Regulation of gene expression may occur at which of the following levels? -Post translation -Constitutive expression -Translation -Transcription

-Post translation -Translation -Transcription

A gene is inducible and under negative control. Which of the following pairs will allow expression of this gene? -Activator + repressor -Activator + inhibitor -Repressor + inducer -Repressor + co-repressor

-Repressor + inducer

Allosteric regulation is accomplished by __________. -a small molecule that fits into an enzyme's active site -a large protein that blocks an enzyme's active site -a small molecule that fits into a site on the enzyme that is not the active site -a small molecule that covalently modifies a site on the enzyme that is not the active site

-a small molecule that fits into a site on the enzyme that is not the active site

The lac repressor __________. -binds to the operator and prevents transcription of the lactose operon -binds to the CAP site and prevents transcription of the lactose operon -binds to the CAP site and facilitates transcription of the lactose operon -binds to the operator and facilitates transcription of the lactose operon

-binds to the operator and prevents transcription of the lactose operon

When glucose is present, __________. -cyclic AMP is high, the catabolite activator protein (CAP) binds to the activator binding site, and transcription of lactose operon is turned on -cyclic AMP is low, CAP binds to the site activator binding site, and transcription of lactose operon is turned on -cyclic AMP is high, CAP does not bind to the activator binding site, and transcription of lactose operon is turned on -cyclic AMP is low, CAP does not bind to the activator binding site, and transcription of the lactose operon is turned off

-cyclic AMP is low, CAP does not bind to the activator binding site, and transcription of the lactose operon is turned off

An activator is present and results in the increase in transcription of the target gene. This is an example of _______________. -termination -positive control -negative control -feedback inhibition

-positive control

When both glucose and lactose are present __________. -cyclic AMP is high so transcription of the lactose operon occurs -the lac repressor binds with the lactose and transcription of the lactose operon occurs -RNA polymerase is able to bind to the operator so transcription of the lactose operon occurs -transcription of the lactose operon is turned off

-transcription of the lactose operon is turned off