photodamage
Quick Summary
Photodamage refers to the detrimental effects of light, particularly ultraviolet (UV) radiation, on biological molecules and cells. When UV light interacts with DNA, it can cause adjacent pyrimidine bases to link together, forming pyrimidine dimers. This damage is mutagenic but can be repaired by an enzyme called photolyase.12
UV radiation can also cause damage through photosensitization, where certain molecules absorb light energy and transfer it to molecular oxygen, creating reactive singlet oxygen. This reactive oxygen can attack cellular compounds, including DNA, leading to processes like light-induced bleaching, a form of photodamage. In plants, this damage necessitates continuous repair and rebuilding of photosynthetic systems. In humans, excessive UV exposure can lead to skin cancers like melanoma and premature skin aging.132
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