KM and Vmax Values Are Important Enzyme Characteristics TABLE 8.4 KM values of some enzymes Enzyme Substrate Km (HM) Chymotrypsin Acetyl-L-tryptophanamide 5000 Lysozyme Hexa-N-acetylglucosamine 6 β-Galactosidase Lactose 4000 Threonine deaminase Threonine 5000 Carbonic anhydrase C02 8000 Penicillinase Benzylpenicillin 50 Pyruvate carboxylase Pyruvate 400 HCO3 1000 ATP 60 Arginine-tRNA synthetase Arginine 3 tRNA 0.4 ATP 300 For most enzymes,KM lies between 10-1 and 10-7 M.KM and V max Values Are Important Enzyme Characteristics For most enzymes, KM lies between 10 - 1 and 10-7 M