Unit 6 - Trp and Lac Operon

Front

What is a repressor?

Back

A protein that binds to the operator region of an operon and blocks RNA polymerase from transcribing the genes.

Front

What happens to the lac operon when lactose is present?

Back

Lactose binds to the repressor, inactivating it, which allows the repressor to release from the operator and enables transcription of the genes.

Front

What is the function of the promoter in eukaryotic gene expression?

Back

The promoter is the binding site for RNA polymerase, initiating the transcription of the gene.

Front

What is the role of operons in prokaryotic gene expression?

Back

Operons regulate gene activity in response to the needs of the cell, allowing for coordinated expression of related genes.

Front

What is an inducer?

Back

A molecule that binds to a repressor and inactivates it, allowing gene transcription to occur.

Front

What is the difference between an inducible operon and a repressible operon?

Back

An inducible operon is usually off and can be turned on in the presence of an inducer, while a repressible operon is usually on and can be turned off in the presence of a corepressor.

Front

What is the function of RNA polymerase?

Back

RNA polymerase is the enzyme responsible for synthesizing RNA from a DNA template during transcription.

Front

What is the operator in an operon?

Back

The operator is a segment of DNA that a repressor binds to, blocking RNA polymerase from transcribing the genes.

Front

What is a corepressor?

Back

A corepressor is a small molecule that cooperates with a repressor protein to switch an operon off.

Front

What is the significance of the lac operon in molecular biology?

Back

The lac operon is a classic example of gene regulation in prokaryotes, illustrating how cells can adapt to changes in their environment.