Explain the operon concept.
Answers
In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter
The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monochromatic mRNAs that are translated separately,
i.e. several strands of mRNA that each encode a single gene product.
The result of this is that the genes contained in the operon are either expressed together or not at all. Several genes must be co-transcribed to define an operon
✏ THE OPERON CONCEPT
■ Jacob and Monod studied lactose catabolism in E.coli.
■ Lactose involves a group of enzyme produced by a group of genes.
■ Operon concept states that each metabolic reaction is controlled by a set of genes.
■ Each operon consist of a group of genes coding for enzyme involved in a particular metabolism pathway.
■ A metabolic pathway is regulated by a unit.
■ All the genes involved in lactose catabolism are called Lac operon.
■ In E.coli, the operon is formed by two types of genes they are structural genes and control genes.
■ The promoter gene is a gene which marks the site at which transcription of mRNA starts.
■ The promoter gene initiates transcription and all the three structural genes synthesis three mRNAs to produce enzymes.