lac operon
Bacterial sugar switch
The lac operon is a cluster of genes in bacteria that controls the metabolism of lactose.
When lactose is present and glucose is absent, these genes switch on together to produce enzymes that break down lactose for energy.
The lac operon became a foundational model in molecular biology for understanding how genes are regulated—how cells turn genes on and off in response to their environment.
- E. coliIntestinal rod-shaped bacterium
- repressorAgent blocking transcription
- inducerSomething that triggers
- glucosePrimary cellular fuel
- beta-galactosidaseLactose-cleaving enzyme
promoter · gene regulation · transcription · Jacob · bacterial · inducible · mRNA · feedback · switch · molecular biology · regulatory · expression
- Bacterial Geneticsplasmid, plasmids, operon, conjugation, transduction
- Gene Expressiongene expression, gene regulation, enhancers, silencer, upregulation
- Protein ExpressionE. coli, plasmid, vector, promoter, transfection
- DNA elementsgene, promoter, enhancer, silencer, exon
- Gene Regulatorsrepressors, activators, enhancers, silencers, promoters
- Operonspromoter, repressor, inducer, attenuator