Fe(II)-heme o + 2 A + H2O <=> Fe(II)-heme a + 2 AH2
fe(ii)-heme o + 2 a + h2o <=> fe(ii)-heme a + 2 ah2
Fe(II)-heme o + 2 A + H2O <=> Fe(II)-heme a + 2 AH2
fe(ii)-heme o + 2 a + h2o <=> fe(ii)-heme a + 2 ah2