Enzymes that prevent the buildup of reactive oxygen molecules in cells. Superoxide dismutase (q.v.) and catalase (q.v.) are the primary enzymes involved in this process. Superoxide dismutase converts the superoxide radical (O2−) to H2O2 and catalase breaks down H2O2 into water and O2. Transgenic Drosophila containing additional copies of the genes encoding superoxide dismutase and catalase have increased longevity. See Chronology, 1994, Orr and Sohol; free radical theory of aging.
Subjects: Genetics and Genomics.