Question

What is an operon in bacteria?

Answer 1

Operon:

1. A group of genes with related functions clustered together with DNA sequences is called operons.
2. It allows the expression of specific genes when required and turns off their expression when not needed.
3. An operon is composed of structural (genes that code for protein ) and regulatory genes( genes involved in regulating the expression of structural genes).
4. Example: Lac operon or lactose operon found in E.coli.

Lac operon in E.coli:

1. It regulates the expression of genes required for the hydrolysis of lactose.
2. Lactose is hydrolyzed into galactose and glucose by the enzyme beta-galactosidase.
3. So when lactose is not present in the cell, lac operon turns off the gene expression required for synthesizing enzyme beta-galactosidase.