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How might the presence/absence of lactose affect the lac operon expression in the context of glucose-mediated...

How might the presence/absence of lactose affect the lac operon expression in the context of glucose-mediated catabolite repression?

Solutions

Expert Solution

In lac operon mechanism lactose is the substrate for the enzyme  β-galactosidase.It regulates switching on and off of the operon.So lactose acts as an inducer in lac operon.

  • In presence of lactose the repressor is inactivated due to the interaction with it.This allows RNA polymerase access to promoter and proceeds transcription.The lac operon is said to be in switch on stage.
  • In absence of lactose the repressor is activated.Hence the repressor binds to the operon resion and prevent RNA polymerase from transcribing the operon.The lac operon is said to be in switch off stage.

gladiator answered 2 years ago
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