光复活修复

又称 光复活.光复活作用是一种高度专一的修复方式，它只作用于紫外线引起的ＤＮＡ嘧啶二聚体（ＤＮＡ分子中同一条链内两个相邻的胸腺嘧啶碱基之间形成 二聚体）。这种二聚体是以共价键联结成 环丁烷的结构而形成的.光复活是由光复活酶催化的.它专一分解嘧啶二聚体.这种酶在生物界分布很广，从 单细胞生物一直到鸟类都有，而高等的 哺乳类动物却没有.这说明在生物进化过程中，光复活作用逐渐被暗修复系统所取代，并丢失了这种酶.Also known as photoreactivation. Photoreactivation repair is a highly specific way, which only act on UV-induced DNA pyrimidine dimer (DNA molecules with a chain between two adjacent thymine bases to form dimer). This dimer is covalently linked into a ring structure of butane formed. Photoreactivation is catalyzed by the enzyme Photoreactivation. It is broken down pyrimidine dimer specificity. This enzyme is widely distributed in the biosphere, from single-celled organism until the birds are, but higher mammals are not. This shows that the biological evolution process, Photoreactivation gradually being replaced by dark repair system, and loss of this enzyme.