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1. Chem a substance added in small amounts to a catalyst to increase its activity
2. Genetics a sequence of nucleotides, associated with a structural gene, that must bind with messenger RNA polymerase before transcription can proceed



a substance added to a catalyst in order to increase its activity, selectivity, or stability. A promoted catalyst is usually a catalyst containing a small amount of a promoter that by itself is catalytically inactive or only slightly active. In the case where the promoter is not inactive, the addition creates a mixed catalyst. Often an additive, given certain external conditions, concentrations, and methods of addition, acts as a promoter, whereas under different conditions the same additive serves as a catalyst poison. Most commercial catalysts belong to the promoted category. For example, V2Os, the catalyst which speeds up the oxidation of SO2 into SO3, is promoted by the oxides of alkali metals; metallic Fe, which catalyzes the synthesis of ammonia, is promoted by the oxides of aluminum, calcium, potassium, and other metals. The mechanism involved in the activity of promoters is explained by modern theories of catalysis.


A chemical which itself is a feeble catalyst, but greatly increases the activity of a given catalyst.
The site on deoxyribonucleic acid to which ribonucleic acid polymerase binds preparatory to initiating transcription of a gene or an operon.


1. A substance which accelerates a chemical reaction but appears to remain unchanged itself.
2. A hardener that accelerates cure of adhesives either with or without heat. Used primarily with synthetic resins.
References in periodicals archive ?
2004-2005 LCO Promoter Technology launched in peanut, alfalfa, and pea/lentil markets.
8] M) for 48 hr displayed a 3-fold increase in transcription from the TH/bZIP promoter (p < 0.
524 (1988) (holding that a taxpayer that relied on the advice of accountants and financial planners who received a fee from the promoter could not avoid penalties); Belle v.
Most vectors constructed for human gene therapy use promoters derived from viruses; Polakowska and Goldsmith's promoter is from a human source.
If investors still remain in contact with promoters, any evidence of statements made by the promoter to the investor (known as "lulling" statements) will prove useful, particularly if promoters make them after investigators already have contacted the promoters and warned them about the true nature of these schemes.
Promoters that require participants to sign confidentiality agreements.
Stuart Lockhart, an owner at Oxford and Wimbledon who breeds greyhounds in Ireland, blasted: "The promoters want not only to own the sport but run it as well.
Mycogen Corporation's Agrigenetics Division, which funded some of Quail's earlier work with the promoter at the University of Wisconsin, is now seeking a patent.
According to the lawyer, the Thompson Committee recommended that 45 cents of every dollar raised by a stock promoter must be spent on property development, with the balance going to the promoter to cover his costs.
We may have to find people who are eating less than 30 percent of their calories from fat to get below a mysterious threshold where fat is a promoter.