Question

What is repressible operon?

Answer 1

Repressible operon:

1. A repressible operon is a type of operon in which the transcription of the gene is repressed by the presence of a particular substance.
2. It is regulated by a co-repressor i.e., mainly the end product of the metabolic pathway.
3. Normally repressible operon is on but in the presence of the co-repressor the pathway becomes off.
4. In the presence of a co-repressor, the transcription is reduced.
5. For example, tryptophan operon, in the presence of tryptophan E.coli doesn't synthesize tryptophan.
6. On the other hand, the inducible pathway is regulated by the substrate present in the metabolic pathway.