Solution to PS 8 #5

Ultravioloet (UV) light can damage DNA by causing dimerization of  thymidylate residues.  One mechanism for repairing thymine dimers is enzymatic photoreactivation, catalyzed by DNA photolase.  This enzyme uses energy from visible light to cleave the dimer and repair DNA.  Thus cells that are exposed to visible light following UV irradation are better able to repair DNA than cells kept in the dark.



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