Nov 13 Operon Regulation

Front

What happens to the trp operon when tryptophan is present in the medium?

Back

The trp operon is turned off when tryptophan is added to the growth medium.

Front

What is the role of the repressor in the trp operon?

Back

The repressor is inactive when tryptophan is absent, allowing RNA polymerase to synthesize mRNA.

Front

What is the function of the repressor in an operon?

Back

To block RNA polymerase when the corresponding substrate (like lactose) is not present.

Front

What is a promoter in gene regulation?

Back

A sequence of DNA where RNA polymerase can bind to start transcription.

Front

What occurs when the repressor binds to the operator in an operon?

Back

It blocks RNA polymerase and prevents mRNA production.

Front

What is the significance of the operator in an operon?

Back

The operator is a segment of DNA that the repressor binds to, regulating the transcription of the operon.

Front

How does the presence of tryptophan affect the repressor's activity?

Back

When tryptophan is present, it binds to the repressor, activating it and allowing it to bind to the operator.

Front

What is the relationship between RNA polymerase and the trp operon?

Back

RNA polymerase binds to the promoter of the trp operon to initiate transcription when tryptophan is absent.

Front

What is feedback inhibition in the context of the trp operon?

Back

Feedback inhibition is a regulatory mechanism where the end product (tryptophan) inhibits its own synthesis by turning off the operon.

Front

What is the difference between an active and inactive repressor?

Back

An active repressor binds to the operator to block transcription, while an inactive repressor does not bind and allows transcription to occur.