A resinous substance secreted as a protective covering by the lac insect, used to make varnish, shellac, sealing wax, dyes, etc.lacquer, lac, shellac, japan, enamel, glaze, polish, oil, resin, waxView synonyms
Late Middle English: from medieval Latin lac, lac(c)a, from Portuguese laca, based on Hindi lākh or Persian lāk.
[attributive] Denoting the ability of normal strains of the bacterium "E. coli" to metabolize lactose, or the genetic factors involved in this ability (which is lost in some mutant strains)
- ‘Other events are correlated with the stable exploration of new niches, like the acquisition of the lac operon by E. coli or pathogenicity islands by Salmonella.’
- ‘In addition to the lac operon, a number of other synthetic and natural genetic circuits have been analyzed for robustness and evolvability.’
- ‘A metabolite of lactose binds to the lac repressor, changing the protein's shape and thereby causing it to loosen its grip on the DNA.’
- ‘This system is probably still the best-understood regulatory system in eukaryotic biology and today is taught in every textbook of genetics and cell biology, alongside the lysis-lysogeny decision of and the lac operon of E. coli.’
- ‘These strains might not even use their lac gene products to metabolize lactose.’
1940s: abbreviation of lactose.
- variant spelling of lakh