In enzymology, a sulfite dehydrogenase (EC 1.8.2.1) is an enzyme that catalyzes the chemical reaction In enzymology, a sulfite dehydrogenase (EC 1.8.2.1) is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are sulfite, ferricytochrome c, and H2O, whereas its 3 products are sulfate, ferrocytochrome c, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donor with a cytochrome as acceptor. The systematic name of this enzyme class is sulfite:ferricytochrome-c oxidoreductase. Other names in common use include sulfite cytochrome c reductase, sulfite-cytochrome c oxidoreductase, and sulfite oxidase. This enzyme participates in sulfur metabolism.