How does lactose get into an E. coli cell if the lac operon is turned "off" and the cell is not synthesizing lactose permease?
Answers
Hey, there!
Here's the answer you are looking for.
Lac operon is under control of negative regulation (according to class 12 NCERT).
Whenever required, the operon is switched on by binding inducer to the repressor protein.
The lactose (inducer) is transported into the cell by the action of PERMEASE, produced by lac y gene.
A very low level of expression of lac operon is present in the cell all the time for lactose to enter into the cell.
Hope that helps!
Thanks.
One of them, the lac repressor, functions as a lactose sensor. - Catabolite activator protein (CAP), on the other hand, functions as a glucose sensor. These proteins bind to the lac operon's DNA and regulate its transcription in response to lactose and glucose levels. Lactose enters the E coli cell in this manner