Photodegradation Processes The Negative Actions of Light

In photobiology these negative actions start with the processes which modify or destroy the essential molecules of life, specifically the nucleic acids and the proteins. The former carry the genetic code in a sequence of nucleotides and even a minor modification of the nucleotide sequence can have profound consequences. By the laws of chance alone these modifications and their consequences are almost always detrimental and result usually in the death of the organism (e.g. microbes) exposed to short-wavelength ultraviolet radiation. 

Many of these degradation processes involve photo-oxidations and these 

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