label: (7Z,10Z,13Z,16Z)-docosatetraenoyl-CoA + 2 Fe(II)-[cytochrome b5] + O2 + 2 H(+) = (4Z,7Z,10Z,13Z,16Z)-docosapentaenoyl-CoA + 2 Fe(III)-[cytochrome b5] + 2 H2O
label_lc: (7z,10z,13z,16z)-docosatetraenoyl-coa + 2 fe(ii)-[cytochrome b5] + o2 + 2 h(+) = (4z,7z,10z,13z,16z)-docosapentaenoyl-coa + 2 fe(iii)-[cytochrome b5] + 2 h2o