Question

Draw the schematic/ diagrammatic presentation of the lac operon.

Answer 1

Hint: The lac operon model observed by Jacob and Monod explains the gene regulation in prokaryotes. Lac operon is an operon that encodes genes for the metabolism of lactose in bacteria.

Complete step by step answer:
Lac operon is the group of genes with a single promoter that encodes the genes for the transportation and metabolism of lactose in E.coli and other Bacteria.

The lac operon model generally explains the gene regulation in prokaryotes. Prokaryotic gene regulation is observed at the initiation of transcription. It is affected by regulation. Regulation takes place normally in the expression of the RNA polymerase at the promoter site. In the case of operons, the operator is right next to the promoter where binding of regulators occurs to control its entire function.
The Lac operon concept was observed and introduced by Jacob and Monod. It consists of:
- Regulator genes that code for the repressor protein
- z gene
- y gene
- a gene

Here z, y, and a gene codes for beta- galactosidase, permease, and transacetylase respectively. Beta- galactosidase can catalyze the hydrolysis of lactose into glucose and galactose. Permease regulates the cell's lactose permeability and transacetylase assists beta-galactosidase.
In the lac operon, lactose is provided in the medium for bacteria to activate the regulatory genes. Thus the inducer binds to the repressor protein and makes it inactive to allow transcription of the operon.

Note: The lac word in lac operon refers to lactose. It consists of the I gene which is a regulatory gene that codes for the repressor of the lac operon and three structural genes mainly z, y, and a. The operon codes for proteins and transports lactose into the cytosol and digests it into glucose. Then the glucose gets used to produce energy.