Nyob rau hauv lom oxidation, ua tiav kev txo qis ntawm oxygen molecule yuav tsum muaj 4 electrons. Yog tias cov pa oxygen molecule tsuas yog txo los ntawm ib qho hluav taws xob ntxiv, cov khoom nruab nrab tsim yog ib pawg superoxide, uas yog, superoxide anion O2 -, uas yog active thiab yooj yim los ua ke nrog ntau yam macromolecular tshuaj los ua. nws inactive.
Cov kab mob tuaj yeem tsim cov pa oxygen thiab cov dawb radicals (xws li superoxide anion) hauv cov txheej txheem metabolic thiab nyob rau hauv ntau yam kev ntxhov siab ib puag ncig, thiab lawv cov tsub zuj zuj yuav ua rau kev puas tsuaj ntawm cov qauv ntawm tes thiab ua haujlwm hauv cov kab mob. Superoxide dismutase (SOD), uas dav muaj nyob rau hauv cov kab mob, yog thawj antioxidant enzyme nyob rau hauv active oxygen scavenging system. SOD disproportionates superoxide anion radicals los tsim hydrogen peroxide thiab molecular oxygen, uas ua lub luag haujlwm tseem ceeb hauv kev tiv thaiv cov hlwb los ntawm kev puas tsuaj oxidative.
