- photoreactivation
- Activation by light of something or of some process previously inactive or inactivated; e.g., pyrimidine dimers, formed in polynucleic acids by the action of UV light, can be monomerized by UV light of a different wavelength via DNA photolyase.
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pho·to·re·ac·ti·va·tion -rē-.ak-tə-'vā-shən n repair of DNA (as of a bacterium) esp. by a light-dependent enzymatic reaction after damage by ultraviolet irradiationpho·to·re·ac·ti·vat·ing -'ak-tə-.vāt-iŋ adj* * *
pho·to·re·ac·ti·va·tion (fo″to-re-ak″tĭ-vaґshən) reversal of the biological effects of ultraviolet radiation on cells by the action of light-dependent enzymes, as in the repair of DNA by the monomerization of dimerized pyrimidines; such repair can impair the efficacy of ultraviolet disinfection. Called also photoreversal.
Medical dictionary. 2011.