Question

The trp and lac operons are regulated in various ways. How do bacteria regulate transcription of these operons? Sort the statements into the appropriate bins depending on whether or not each operon would be transcribed under the stated conditions.lac operon: lactose absentlac operon: lactose and glucose presentlac operon: lactose present, glucose nottrp operon: tryptophan presenttrp operon: tryptophan absentI Operon is not transcribed:II Operon is transcribed, but not sped up throughIII Operon is transcribed, but not sped up through

Answer 1

Answer:

Operon is not transcribed:

-lac operon: lactose absent

-trp operon: tryptophan present

Operon is transcribed, but not sped up through positive control:

-lac operon: lactose and glucose present

-trp operon: tryptophan absent

Operon is transcribed quickly through positive control:

-lac operon: lactose present, glucose not

Explanation:

The trp operon is controlled via negative control only.

Presence of tryptophan will inhibit the transcription of the operon genes

The lac operon is controlled via negative control and positive control.

●Negative control:

--Transcription is turned off due to

active Repressor protein and absence of lactose

--Transcription is turned on due to

Inactive Repressor protein and presence of lactose

●Positive control:

--Transcription rate is higher due to absence of transcription and presence of lactose as a regulatory protein (CAP) adhere to the lac operon promoter