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
