Lac Operon Explained in One Shot | Gene Regulation | Join crash course and restart For #reneet2026

Added: 2026-05-21

[00:00:04]Now let's understand the basic structure. Now, I gene is the regulator.

[00:00:09]It codes for the repressor protein.

[00:00:11]Okay?

[00:00:16]It will go and bind to the operator, which is over here. Now the repressor binds over here and it blocks transcription.

[00:00:27]Now P is for promoter. The RNA polymerase binds over here to begin transcription.

[00:00:35]Now let's say lactose cell may not be here. So obviously glucose will be preferred as the carbon source. So the repressor proteins become active. What will it do? It will bind to the operator very tightly. So the RNA polymerase is blocked and transcription of lacZ, Y, and A is off. Now let's say lactose is added. So lactose enters the cell. It is converted to allolactose, which is the inducer.

[00:01:00]Now allolactose binds to the repressor.

[00:01:03]So the repressor changes shape and it is inactivated. So here the operator is free. So RNA polymerase transcribe lacZ, Y, and A and this produces protein. Now let me give you a simple equation.

[00:01:15]Allolactose, which is the inducer, this inactivates the repressor. So the operator becomes free and the mRNA is made. Doctors, don't forget to join my Telegram channel. We will be sharing all the updates over there with many such reels and PDFs.