Lac Operon HB 24/25

Front

What is the function of the inducer in the lac operon?

Back

The inducer binds to the repressor, causing it to change shape and release from the operator, allowing RNA polymerase to transcribe the genes necessary for lactose metabolism.

Front

What role does the repressor play in the lac operon?

Back

The repressor binds to the operator region of the lac operon, blocking RNA polymerase from transcribing the genes when lactose is not present.

Front

What is the operator in the context of the lac operon?

Back

The operator is a segment of DNA where the repressor binds, preventing transcription of the downstream genes.

Front

What is the promoter in the lac operon?

Back

The promoter is the region of DNA where RNA polymerase binds to initiate transcription of the lac operon genes.

Front

What happens when lactose is present in the environment of a bacterial cell?

Back

Lactose acts as an inducer, binding to the repressor and allowing transcription of the lac operon genes to occur.

Front

What is the significance of the lac operon in bacteria?

Back

The lac operon allows bacteria to efficiently utilize lactose as an energy source when glucose is not available.

Front

Define 'corepressor' in the context of gene regulation.

Back

A corepressor is a molecule that binds to a repressor protein, enhancing its ability to bind to the operator and inhibit transcription.

Front

Explain the concept of negative regulation in the lac operon.

Back

Negative regulation occurs when a repressor protein binds to the operator to prevent transcription, effectively turning off gene expression.

Front

What is the difference between an inducer and a corepressor?

Back

An inducer activates gene expression by inhibiting the repressor, while a corepressor enhances the repressor's ability to inhibit transcription.

Front

Describe the process of transcription initiation in the lac operon.

Back

Transcription initiation occurs when RNA polymerase binds to the promoter after the repressor is removed by the inducer, allowing the genes to be transcribed.