<unk> s are a set of enzymes that catalyse the oxidation of<unk>  to bicarbonate, donating the electrons to a second substrate, such as NAD+ in<unk> :NAD+ oxidoreductase (EC 1.2.1.2) or to a cytochrome in<unk> :ferricytochrome-b1 oxidoreductase (EC 1.2.2.1).
NAD-dependent<unk> s are important in methylotrophic yeast and bacteria and are vital in the catabolism of C1 compounds such as methanol. The cytochrome-dependent enzymes are more important in anaerobic metabolism in prokaryotes. For example, in E. coli, the<unk> :ferricytochrome-b1 oxidoreductase is an intrinsic membrane protein with two subunits and is involved in anaerobic nitrate respiration.
NAD-dependent reaction<unk>  + NAD(+) <=> CO(2) + NADH
Cytochrome-dependent reaction<unk>  + 2 ferricytochrome b1 <=> CO(2) + 2 ferrocytochrome b1 + 2 H(+)
Formate dehydrogenase
Aldehyde dehydrogenase
Oxoglutarate dehydrogenase
Succinate dehydrogenase
D-amino acid dehydrogenase
Phosphoglucomutase
Glucose-6-phosphate dehydrogenase
Saruplase