Initial Velocity Assumption E+S名S冬E+P In the beginning of the reaction,there is very little product,or [P]is small.So the amount of [ES]contributed by E+P is negligible. Thus,the MM equation concerns the reaction rate that is measured during early reaction period. In which case,the enzyme catalyzed reaction can be modified to: E+S →ES E+P K Initial Velocity Assumption • In the beginning of the reaction, there is very little product, or [P] is small. So the amount of [ES] contributed by E+P is negligible. • Thus, the MM equation concerns the reaction rate that is measured during early reaction period. • In which case, the enzyme catalyzed reaction can be modified to: • K-1 E + S ES E + P k1 K-1 k2 E + S ES E + P k1 k2 K-2