Fe(II)-heme i + A + H2O = Fe(II)-hydroxyheme i + AH2
fe(ii)-heme i + a + h2o = fe(ii)-hydroxyheme i + ah2
Fe(II)-heme i + A + H2O = Fe(II)-hydroxyheme i + AH2
fe(ii)-heme i + a + h2o = fe(ii)-hydroxyheme i + ah2