ENZYMES DO not make reactions to take place, but they stimulate the reaction and therefore enhance the reaction rate by reducing the activation energy necessary for the reaction to occur. Understanding the kinetic behaviour of an enzyme or an enzymatic system means also to understand much of the underlying enzymatic mechanism[74]. To acquire kinetic parameters of enzymatic reactions, investigations of the reaction under well-defined conditions are necessary.
Chemical reactions may be described as a set of ordinary differential equations (ODE) describing the rate for each compound. These differential equations may be used to simulate enzymatic reactions if the kinetic parameters are known[23]. For parameter estimations, ODEs are more difficult to use because of the large amount of variables and the numerical difficulties in solving a large set of differential equations. For this reason, equations are developed to describe the reaction (either exact or as approximation) which may be better used for parameter estimation.