Free radicals are a normal byproduct of metabolism, but their accumulation may be a molecular cause for aging. (discovermagazine.com)
But organisms from humans to algae also have another clock that doesn't rely on rhythmic gene expression to keep time, but instead uses the rise and fall of the reactive oxygen molecules that are formed as natural byproducts of metabolism. (sciencedaily.com)
This often involves restoring injured nucleic acids back to their native form or replenishing proteins and lipids once damaged by harmful byproducts of metabolism. (fightaging.org)