Operon

Definition

An operon is a cluster of genes under the control of a single promoter and regulated together, allowing for coordinated expression. Common in prokaryotes, they facilitate efficient gene regulation.

5 Must Know Facts For Your Next Test

1. Operons consist of structural genes, a promoter, and an operator.
2. The lac operon in E. coli is a classic example that controls lactose metabolism.
3. Repressors can bind to the operator to prevent transcription.
4. Inducers can deactivate repressors to initiate gene expression.
5. Operons allow prokaryotes to adapt quickly to environmental changes by regulating multiple genes simultaneously.

Review Questions

• What components make up an operon?
• How does the repressor function in an operon?
• Give an example of an operon and describe its role.

Related terms

Promoter:

A DNA sequence where RNA polymerase binds to initiate transcription.

Operator:

A segment of DNA to which a repressor binds, inhibiting RNA polymerase action.

Repressor:

A protein that binds to the operator and blocks transcription by preventing RNA polymerase from attaching.