What does the lac operon consist of? How is the operator switch turned on and off in the expression of genes in this operon? Explain.
Lac Operon consists of the following : Structural genes: z, y, a which transcribe a polycistronic mRNA. gene ‘z’ codes for b-galactosidase gene' codes for permease. gene‘a’ codes for transacetylase. Promotor: The site where RNA polymerase binds for transcription. Operator: acts as a switch for the operon. Repressor: It binds to the operator and prevents the RNA polymerase from transcribing. Inducer: Lactose is the inducer that inactivates the repressor by binding to it. Allows access for the RNA polymerase to the structural gene and transcription.
