In E.coli during lactose metabolism repressor binds to[2002]a)regulator geneb)operator genec)structural gened)promoter geneCorrect answer is option 'B'. Can you explain this answer?

Question

Answer

Answer

Operator region is main if reprasor to operator region it can not leads to synthesis of mrna molecule and enzymes

Answer

Repressor protein bind to operator gene which result in the blockage of ribosomalRNA as a result structural gene are not transcribe due to which lac operon is off.

Answer

Explanation:

During lactose metabolism in E.coli, the lac operon is responsible for the expression of genes involved in lactose utilization. The lac operon consists of three main components - the regulator gene, the operator gene, and the structural gene.

Regulator Gene:
The regulator gene, also known as the lacI gene, codes for the synthesis of the lac repressor protein. The lac repressor protein binds to the operator gene and regulates the expression of the structural genes.

Operator Gene:
The operator gene is a DNA sequence located between the promoter gene and the structural gene. It acts as a binding site for the lac repressor protein. When lactose is absent, the lac repressor protein binds to the operator gene, preventing the RNA polymerase from binding to the promoter gene.

Structural Gene:
The structural gene in the lac operon is the lacZ gene, which codes for the enzyme β-galactosidase. β-galactosidase is responsible for the hydrolysis of lactose into glucose and galactose, allowing E.coli to utilize lactose as a carbon source.

Promoter Gene:
The promoter gene is located upstream of the operator gene and is responsible for initiating the transcription of the structural gene. It provides a binding site for RNA polymerase, which initiates transcription by binding to the promoter gene.

Explanation of the Correct Answer:
In the given question, it is stated that during lactose metabolism, the repressor binds. Since the repressor protein binds to the operator gene in the lac operon, the correct answer is option 'B' - operator gene.

The binding of the lac repressor to the operator gene prevents the RNA polymerase from binding to the promoter gene, inhibiting the transcription of the structural gene. This mechanism ensures that the genes involved in lactose metabolism are only expressed when lactose is present in the environment.

By binding to the operator gene, the lac repressor acts as a negative regulator, controlling the expression of the lac operon. When lactose is available, it binds to the lac repressor, causing a conformational change that prevents it from binding to the operator gene. This allows the RNA polymerase to bind to the promoter gene and initiate transcription of the structural gene, enabling the utilization of lactose by E.coli.

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In E.coli, during lactose metabolism repressor binds to

In E.coli, during lactose metabolism repressor binds to

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