Explanatory notes
… may be either a metal ion (e.g., copper in ascorbate oxidase, zinc in human placental alkaline phosphatase) or a … in pyruvate decarboxylase, pyridoxal phosphate in glutamine-oxo-acid aminotransferase). Sometimes both are required. … (II) According to : (a) their chemical activity as oxidoreductases, transferases, hydrolases, lyases, …