Gene regulation in eukaryotes works by transcriptional activators and repressors. The repressors hold to specific DNA sequences and inhibit transcription. In eukaryotes, transcription involves several steps. It occurs in both, nucleus (transcription) and cytoplasm (translation).
Lac operon contains genes involved in metabolism. The genes are expressed only when lactose is present and glucose is absent.
The operon is put in on and off mode in response to the glucose and lactose levels: catabolite activator protein and lac repressor.
The lac repressor comes in the way of transcription of the operon. In the presence of lactose, it stops acting as a repressor. Catabolite activator protein activates the transcription of the operon, only glucose levels are low.
Define LAC Operon
Lac operon is an operon or a gaggle of genes with one promoter that encode genes for the transport and metabolism of lactose in E.coli and other bacteria.
2. What is the concept of LAC Operon?
Gene regulation in prokaryotes are often explained with the assistance of the Lac Operon model. Here the alteration in physiological and environmental conditions is often observed resulting in an alteration in expression in prokaryotes. It was observed by Jacob and Monod. The lac operon consists of:
Regulatory gene i – It codes for the repressor protein.
z gene – It codes for beta-galactosidase which catalyzes the hydrolysis of lactose into glucose and galactose.
y gene – It codes for permease which regulates the lactose permeability within the cell.
a gene – It codes for transacetylase which assists the enzyme beta-galactosidase.
Share your contact information
Vedantu academic counsellor will be calling you shortly for your Online Counselling session.