Trp Operon Exam Latest Update
The tryptophan operon is a ______________ operon. - Answer The tryptophan operon is a
repressible operon.
The tryptophan operon is involved in the synthesis of - Answer tryptophan.
What happens to the this system when tryptophan is plentiful? - Answer It shuts down.
Is tryptophan expensive? - Answer Tryptophan is expensive to build and several steps
are necessary to build it.
What role does tryptophan play in this system? - Answer Tryptophan is a corepressor; it
is required for the repressor (trpRP) to bind to the operator and stop transcription.
How many structural proteins are on the Trp Operon? - Answer 5. They are preceeded
by the regulatory region.
What is an attenuator region? - Answer A control region following the promoter of
repressible amino acids that exerts transcriptional control of the polycistronic mRNA
based on the translation of the small leader peptide gene.
In the correct order, list the Trp Operon genes. - Answer TrpE, TrpD, TrpC, TrpB, TrpA
Trp Synthesis is an example of __________ - Answer polycistronic mRNA. It is translated
into 5 distinct polypeptides.
How many binding sites are on the trp repressor protein? Name them. - Answer 2: one
for Trp and the other for the operator.
What happens when Trp is abundant? - Answer Trp binds the repressor protein. The
repressor protein changes shape, exposing the operator binding site. The repressor
protein binds the operator. Transcription ceases.
What happens when tryptophan levels are very low? - Answer Trp does not attach to the
repressor protein. There is no functional binding site for the operator on the repressor
protein. Transcription occurs. (because the repressor isn't repressing)
Are the Trp operon and Lac Operon under the same regulatory control mechanisms?
Compare them. - Answer No; they have a different repression promotion.
Trp: RP bound to operator when Trp is present.
RP released when Trp is absent.
When bound to RP, RP changes shape to open operator binding site
Negative regulation
The tryptophan operon is a ______________ operon. - Answer The tryptophan operon is a
repressible operon.
The tryptophan operon is involved in the synthesis of - Answer tryptophan.
What happens to the this system when tryptophan is plentiful? - Answer It shuts down.
Is tryptophan expensive? - Answer Tryptophan is expensive to build and several steps
are necessary to build it.
What role does tryptophan play in this system? - Answer Tryptophan is a corepressor; it
is required for the repressor (trpRP) to bind to the operator and stop transcription.
How many structural proteins are on the Trp Operon? - Answer 5. They are preceeded
by the regulatory region.
What is an attenuator region? - Answer A control region following the promoter of
repressible amino acids that exerts transcriptional control of the polycistronic mRNA
based on the translation of the small leader peptide gene.
In the correct order, list the Trp Operon genes. - Answer TrpE, TrpD, TrpC, TrpB, TrpA
Trp Synthesis is an example of __________ - Answer polycistronic mRNA. It is translated
into 5 distinct polypeptides.
How many binding sites are on the trp repressor protein? Name them. - Answer 2: one
for Trp and the other for the operator.
What happens when Trp is abundant? - Answer Trp binds the repressor protein. The
repressor protein changes shape, exposing the operator binding site. The repressor
protein binds the operator. Transcription ceases.
What happens when tryptophan levels are very low? - Answer Trp does not attach to the
repressor protein. There is no functional binding site for the operator on the repressor
protein. Transcription occurs. (because the repressor isn't repressing)
Are the Trp operon and Lac Operon under the same regulatory control mechanisms?
Compare them. - Answer No; they have a different repression promotion.
Trp: RP bound to operator when Trp is present.
RP released when Trp is absent.
When bound to RP, RP changes shape to open operator binding site
Negative regulation
