The Lac Operon exam Flashcards

An inducible operon in E. coli that includes genes for lactose metabolism.

lacZ, lacY, and lacA.

The repressor protein that binds to the operator to block transcription in the absence of lactose.

The lacI repressor binds to the operator, blocking transcription.

A derivative of lactose that inactivates the lacI repressor, allowing transcription.

It initiates transcription of the lac operon genes when the repressor is inactive.

An operon that is normally off but can be turned on in the presence of a specific inducer.

Encodes β-galactosidase, an enzyme that breaks down lactose.

Encodes permease, which facilitates the entry of lactose into the cell.

Encodes transacetylase, an enzyme involved in lactose metabolism.

A DNA segment where the repressor binds to block transcription.

The presence of allolactose.

It ensures energy efficiency by activating only when lactose is available and glucose is absent.

Allolactose inactivates the repressor, allowing transcription of the operon.

The concept that the lac operon is only activated when necessary to conserve energy.

The lac operon is only activated when lactose is present and glucose is absent.

An enzyme that breaks down lactose into glucose and galactose.

Facilitates the entry of lactose into the bacterial cell.

A protein that binds to the operator to prevent transcription.

E. coli.

A sugar that can be metabolized by the enzymes encoded by the lac operon.

An enzyme involved in the metabolism of lactose.

A molecule that initiates gene expression by inactivating a repressor.

A DNA sequence where RNA polymerase binds to start transcription of the lac operon.