Question

If E.coli is grown in a medium containing glucose and maltose in equal amounts, the glucose is broken down immediately followed by the maltose at a slower rate. This diauxic growth is an example of the use of _________.

Answer 1

Catabolite repression

Explanation:

1. Catabolite repression: it is the positive control of the lac operon.

2. It results in an increase in the rate of transcription. Here, the CAP protein is activated by cAMP which then bind to the lac operon and facilitate the binding of RNA polymerase to the promoter to transcribe the genes for lactose utilization.

3. Role of glucose in catabolite repression is that It stimulates transcription from the lac operon, causing an increase in cAMP levels in the cell. Glucose decreases the levels of cAMP in the cell, result in repressing transcription from the lac operon.