Lac operon

Definition

The lactose operon is an operon required for the transport and metabolism of lactose in E. coli and many other enteric bacteria. Although glucose is the preferred carbon source for most enteric bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available through the activity of β-galactosidase. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes for this reason. This lactose metabolism system was used by François Jacob and Jacques Monod to determine how a biological cell knows which enzyme to synthesize. Their work on the lac operon won them the Nobel Prize in Physiology in 1965.

Related concepts

Acetyl group Activator (genetics)Allolactose Allosteric protein Archaeal transcription factor B B recognition element Bacillus subtilis Bacterial transcription Beta-galactosidase Beta-galactoside permease Beta-galactoside transacetylase Biological cell C. H. Waddington CAAT box CAMP receptor protein CHD7 Canalisation (genetics)Catabolic pathway Catabolite activator protein Catabolite repression Cell (biology)Cell growth Cellular biology Cellular transport Christiane Nüsslein-Volhard Chromatin remodeling Cis-regulatory element Coactivator (genetics)Complementation (genetics)Corepressor Cyclic adenosine monophosphate Cytoplasmic membrane DLX gene family DNA DNA-binding protein DNA methylation DNA methyltransferase Demethylase Developmental biology Diauxie Disaccharide Dominance (genetics)Dual inheritance theory E-box E. coli EZH2 Endless Forms Most Beautiful (book)Engrailed (gene)Enhancer (genetics)Enzyme Epigenetics Epistasis Eric F. Wieschaus Eukaryotic transcription Evo-devo gene toolkit Evolution of sexual reproduction Evolutionary developmental biology Evolutionary landscape Evolutionary tinkering Evolvability Eyespot (mimicry)Fitness landscape François Jacob Gab operon Gal operon Galactose Galactoside GenBank Gene expression Gene regulation Gene regulatory network Genetic architecture Genetic assimilation Gene–environment correlation Gene–environment interaction Genomic imprinting Genotype–phenotype distinction Glucose Growth curve (biology)Gua Operon Gut flora HDAC1 Hedgehog signaling pathway Heritability Heterochrony Heterotopy Histone Histone-modifying enzymes Histone acetylation and deacetylation Histone acetyltransferase Histone deacetylase Histone methylation Histone methyltransferase Homeobox Homeotic gene Hox gene Hydrolysis IPTG In vitro In vivo Index of evolutionary biology articles Inducer Insulator (genetics)Internal control region Intrinsic termination Intron Isomer Jacques Monod Journal of Molecular Biology L-arabinose operon LacI LacY Lac repressor Laci (disambiguation)Lactose Lacy (disambiguation)Ligand (biochemistry)Luria-Bertani broth MRNA MacConkey agar Maternal effect Medical Subject Headings Membrane protein Metabolism Metamerism (biology)Michael Levine (biologist)Microorganism Modularity (biology)Molecular biology Morphogen Morphogenesis Morphogenetic field Nature versus nurture Neoteny Neutral network (evolution)Nobel Prize in Physiology Notch signaling pathway Nuclear envelope Nucleosome ONPG Operator (biology)Operon Ortho-Nitrophenyl-β-galactoside Orthonitrophenol PAX6 PEP group translocation Pattern formation Pax genes Phenotype Phenotypic plasticity Phenyl-β-D-galactose Phosphoenolpyruvic acid Pleiotropy Polycistronic Polygenic inheritance Polyphenism Pribnow box Primary transcript Prokaryote Promoter (biology)Promoter (genetics)Quantitative genetics RNA polymerase RNA polymerase II Reaction norm Receptor (biochemistry)Regulation of gene expression Regulator gene Reporter gene Repressor Response element Rho factor Richard H. Ebright Richard Lewontin Robustness (evolution)RpoB Sean B. Carroll Segmentation (biology)Sequence space (evolution)Shine-Dalgarno sequence Silencer (DNA)Streptomycin Structural gene Substrate (biochemistry)Sugar Symporter TATA box Terminator (genetics)Tetrazolium Thiomethyl galactoside Transcription (genetics)Transcription coregulator Transcription factor Transcriptional activator Transcriptional regulation Transgressive segregation Translation (genetics)Transport protein Trp operon Tryptophan repressor Two hybrid Upstream and downstream (DNA)William McGinnis World War II X-gal Β-Galactosidase

32 concepts already in your glossary