Which of the following is correct regarding the function of the lac repressor protein?
A)In the presence of allolactose,the protein binds the operator inhibiting transcription.
B)In the absence of allolactose,the protein binds the operator inhibiting transcription.
C)In the presence of allolactose,the protein binds the operator enhancing transcription.
D)In the absence of allolactose,the protein binds the operator enhancing transcription.
E)None of the above.

Question

Quizplus · Accepted Answer

In the absence of allolactose, the lac repressor protein binds to the operator, inhibiting transcription. This is because the repressor protein is synthesized constitutively and binds the operator region of the lac operon, which overlaps with the promoter region. When the repressor protein binds the operator, it hinders the RNA polymerase from binding the promoter and the transcription does not occur. In the presence of allolactose, the inducer binds to the repressor protein, causing a conformational change that makes the repressor release from the operator region, allowing RNA polymerase to initiate transcription.

Which of the Following Is Correct Regarding the Function of the Lac