Explain how metabolic pathways are regulated?

Question

Explain how metabolic pathways are regulated?

Answer 1

Metabolic pathways can be regulated induction and repression.

A simple example is the lactose operon in the bacterium  E. coli.  When grown in the absence of lactose the lactose operon is repressed by the lacI repressor that prevents transcription of the lactose operon genes.  When lactose is present in the growth media the lactose molecules interact with the lacI repressor causing release from the lactose operon promoter region thus allowing transcription of the lactose operon genes which will metabolize lactose.  Once all of the lactose is used up in the media the lacI repressor will again inhibit lactose operon transcription.

So in the case of lactose metabolism it is repressed by the lactose operon repressor, lacI, and induced by its substrate lactose.