Question

What happens to lac repressors in E. coli when lactose is present

Answer 1

Step-by-step explanation:

the presence of lactose causes the lac repressor protein to undergo a conformational change that prevents it from binding to the operator region of the lac operon, allowing for the transcription of the lac genes and metabolism of lactose in E. coli.

Answer 2

In E. coli, the lac operon is responsible for the metabolism of lactose. The lac operon consists of three genes: lacZ, lacY, and lacA, which encode for the enzymes required for the breakdown of lactose. The expression of these genes is regulated by the lac repressor protein, which binds to the operator region of the lac operon in the absence of lactose, preventing the transcription of the genes.

When lactose is present in the environment, it binds to the lac repressor protein and causes a conformational change that prevents it from binding to the operator region of the lac operon. This allows RNA polymerase to bind to the promoter region and initiate transcription of the lac genes, leading to the production of the enzymes required for lactose metabolism.

In summary, the presence of lactose causes the lac repressor protein to undergo a conformational change that prevents it from binding to the operator region of the lac operon, allowing for the transcription of the lac genes and metabolism of lactose in E. coli.