Identify correct statements about 'Enzyme'. A. Enzymes are the protein biocatalysts which are synthesized by the living cells. B. An enzyme is specific in its action, possessing active site. C. Enzyme activities are inhibited by only reversible manner. D. Many enzymes require certain non-protein substrate called cofactor for their action. E. Estimation of serum enzymes is of great help in the diagnosis of several diseases. Choose the correct answer from the options given below: