Description of the lac Operon

Parts of the operon and their functions - Click the button to locate each part

• Repressor Gene - Produces a repressor protein that fits in the operator to turn the operon off
• Promoter - RNA polymerase attaches here to begin transcription of the genes
• Operator - The active repressor fits in notches to block RNA polymerase and turn off transcription.
• Structural Genes - Metabolic pathway genes with code for enzymes to digest lacotse