Lac Operon : Gene regulation || Operon Theory || Biology

Application of #Operon Theory by Mizanur Rahman
#Biology lectures
"Today I’m going to discuss you about application of operon theory.
First of all we have to know what is operon.
Operon is gene action. How a gene acts or reacts.50% work of central dogma is done by operon.
Now the question is what happens, when an e. choli cell is placed into a glucose medium from a lactose medium?
So it is easy to answer that the operon of the cell stops to work.
Now why it doesn’t work?
In operon theory from a DNA stand an mRNA is produced . This mRNA produces some repressor proteins. In lactose medium this repressor protein is repressed by the lactose of the lactose medium. The lactose changes the repressor protein’s allosteric shape and makes a lactose repressor protein complex. So the polycystronic mRNA is continuously produced. This mRNA produces some proteins in the form of enzyme. These enzymes are beta-galactosidase, lac-permiase, trans-acitylase.
Now how the operon is repressed? Interestingly in glucose medium beta-galactosydase acts on lactose repressor protein complex and breaks down the lactose into glucose and galactose.
Finally repressor protein is free from this repressor protein complex and it represses the operon to work. "

Studio : #rPiXY
Editor: Ashique Imran