| 释义 |
noun laklæk mass nounA resinous substance secreted as a protective covering by the lac insect, used to make varnish, shellac, sealing wax, dyes, etc. 紫胶 Synonyms lacquer, shellac, japan, enamel, glaze, polish, oil, resin, wax
OriginLate Middle English: from medieval Latin lac, lac(c)a, from Portuguese laca, based on Hindi lākh or Persian lāk. adjectivelaklæk Biology 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) 〔生〕具乳糖代谢能力的 乳糖操纵子。 Example sentencesExamples - These strains might not even use their lac gene products to metabolize lactose.
- 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.
- In addition to the lac operon, a number of other synthetic and natural genetic circuits have been analyzed for robustness and evolvability.
- 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.
Origin1940s: abbreviation of lactose. abbreviation (in the RAF) Leading Aircraftman or Leading Aircraftwoman.
nounlæklak A resinous substance secreted as a protective covering by the lac insect, used to make varnish, shellac, sealing wax, dyes, etc. 紫胶 Synonyms lacquer, shellac, japan, enamel, glaze, polish, oil, resin, wax
OriginLate Middle English: from medieval Latin lac, lac(c)a, from Portuguese laca, based on Hindi lākh or Persian lāk. adjectivelæklak Biology 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) 〔生〕具乳糖代谢能力的 乳糖操纵子。 Example sentencesExamples - 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.
- 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.
- In addition to the lac operon, a number of other synthetic and natural genetic circuits have been analyzed for robustness and evolvability.
- These strains might not even use their lac gene products to metabolize lactose.
Origin1940s: abbreviation of lactose. |