The lactose (lac) operon in E. coli is an example of a gene that is repressed when lactose is not available in a cell. In 3-5 sentences, explain what this means, using correct terminology..
When lactose is not available in a cell, the lac repressor protein binds to the operator region of the lac operon. This binding prevents RNA polymerase from transcribing the genes necessary for lactose metabolism. As a result, the structural genes of the lac operon, such as lacZ, lacY, and lacA, are not expressed. This repression ensures that the cell does not waste energy producing proteins for metabolizing lactose when it is not present in the environment.
use simpler terms
When there is no lactose around, a protein called the lac repressor stops the genes in the lac operon from being turned on. This means that the cell doesn't make the proteins needed to digest lactose because there's no point if there's no lactose to digest. This helps the cell save energy by only making the necessary proteins when they are needed.
