The lactose (lac) operon in E. coli is a gene that helps break down lactose in the cell. If there is no lactose present, the operon is repressed. In 2 sentences , explain how the lac operon is used and repressed in cells. Use the following words in your response: operon, operator, repressor, RNA polymerase, and transcribe/transcription. (4 points)

Answer 1

In the absence of lactose, the lac operon is repressed when a repressor protein binds to the operator region, preventing RNA polymerase from transcribing the genes necessary for lactose metabolism. When lactose is present, it binds to the repressor, causing a conformational change that releases the repressor from the operator, allowing RNA polymerase to transcribe the operon and produce the enzymes needed to break down lactose.