Question

Give four differences between an inducible and a repressible operon.

Answer 1

Differences between Inducible and Repressible Operon

Inducible Operon	Repressible Operon
1. It involves the switching on of an operon which normally remains turned off.	1. It involves turning off of an operon which normally remains switched on.
2. It is switched on in response to a new substrate which is to be handled and metabolised.	2. Repressible operon is stopped by increased formation or availability of a metabolite.
3. It is generally connected with a catabolic pathway.	3. It is mostly connected with an anabolic pathway.
4. The regulator gene of an operon produces a repressor that blocks the operator gene.	4. The regulator gene of an operon, produces a the repressor called aporepressor. The same cannot block the operator gene.
5. It involves the removal of the repressor of an operon by the inducer metabolite	5. It involves the blocking of the operator gene of operon through a complex repressor that is formed union of aporepressor formed by regulator gene corepressor which is actually a product of anabolic pathway
6. In this inducer is substrate, hormone or its by product.	6. In this repressor is a compound formed by an aporepressor and a corepressor which is commonly an end product of metabolic pathway.
7. It brings about transcription and translation.	7. Repression stops transcription and translation.