Much of the damage looks like the result of oxidation by free radicals (oxygen-rich compounds released during cellular energy production).

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These free radicals are oxygen-rich molecules in which one of the oxygen atoms is particularly likely to react with other chemicals.

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They then have nowhere to put all the light energy they are absorbing, and the resulting breakdown of biochemical pathways creates toxic oxygen-containing molecules known as free radicals.

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Such reactions, though, often create damaging oxygen-rich molecules called free radicals, which are thought to be one of the driving forces of ageing.

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