It allows lactose to permeate the cell membrane, and then break bonds with glucose and galactose to use the lactose for food.
The lac genes in E. coli are regulated by the lac operon, which is controlled by a repressor protein. The repressor binds to the operator region of the DNA, blocking the transcription of the lac genes. When lactose is present, it binds to the repressor, causing a conformational change that releases the repressor from the operator, allowing for the expression of the lac genes.
A lac repressor turns off the lac genes by binding to the operator.
The other region is the OPERATOR (O) e coli cells contains several copies of a DNA binding proteins known as the lac repressor, which can be bind to the O region your answer: Operator
The lac repressor can be likened to a security guard at a gate. When lactose is not present, the lac repressor binds to the operator region of the lac operon, preventing RNA polymerase from transcribing genes for lactose metabolism. Just like how the security guard restricts entry to unauthorized individuals, the lac repressor restricts gene expression in the absence of lactose.
Gene expression is blocked in the lac operon system when the lac repressor binds to the operator in the presence of lactose. This prevents RNA polymerase from transcribing the genes, keeping the system off until lactose is available to derepress the operon.
That statement is inaccurate. The lac repressor releases the operator in the absence of glucose but in the presence of lactose. Glucose acts as a catabolite activator protein (CAP) regulator in the lac operon system.
repressor gene
My answer is 3, I am pretty sure I am right, but I would double check to make sure. I am in ninth grade taking biology at PineTree.
When the lac operon controls the expression of proteins in the E.coli cell that can break down lactose into two sugars, glucose and galactose. When lactose is present, it binds to the repressor that typically sits on the lac operon, changing the repressor's conformation such that it can no longer bind to the lac operon. Because of this, RNA polymerase can now transcribe the gene into mRNA, which in turn is translated into the proteins that can break down lactose.
When the lac operon controls the expression of proteins in the E.coli cell that can break down lactose into two sugars, glucose and galactose. When lactose is present, it binds to the repressor that typically sits on the lac operon, changing the repressor's conformation such that it can no longer bind to the lac operon. Because of this, RNA polymerase can now transcribe the gene into mRNA, which in turn is translated into the proteins that can break down lactose.
A lac repressor turns off the lac genes by binding to the operator
The lac operon is a group of genes involved in metabolizing lactose. The protein Lac repressor binds to the operator site in the absence of lactose, blocking gene expression. When lactose is present, it binds to the Lac repressor, causing it to release from the operator and allowing transcription of the genes involved in lactose metabolism.