- s. dismutase (SOD) an enzyme that catalyzes the dismutation reaction, 2O2 − + 2H+ → H2O2 + O2; there are three isozymes of SOD: an extracellular form (ECSOD) that contains copper and zinc, a cytoplasmic form that also contains copper and zinc, and a mitochondrial form that contains manganese; a deficiency of SOD is associated with amyotrophic lateral sclerosis.
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su·per·ox·ide -'äk-.sīd n any of various toxic oxygen-containing free radicals esp the monovalent anion O2- or a compound containing it <potassium \superoxide KO2>
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su·per·ox·ide (soo″pər-okґsīd) any compound containing the highly reactive superoxide radical, O2−, which is produced by reduction of molecular oxygen in many biological oxidations; this highly toxic free radical is continuously removed by the enzyme superoxide dismutase.Medical dictionary. 2011.