Determination of Kinetic Parameters for Irreversible and Reversible One-Substrate Reactions

2 Determination of Kinetic Parameters for Irreversible and Reversible One-Substrate Reactions 

For simple kinetic mechanisms, like irreversible one-substrate reactions, both rapid equilibrium and steady-state hypothesis lead to rate equations that are formally equal in parametric terms, so when those parameters are experimentally determined, results are the same no matter what hypothesis is considered. Kinetic parameters are to be experimentally determined to obtain validated rate expressions to be used for the design or performance evaluation of enzyme reactors. 

There are several methods for the determinations of kinetic parameters, most of them based on initial rate measurements at varying substrate concentrations alternatively they can be determined from the time course of the enzymatic reaction. 

Experimental design for determination based on initial rates consists in a series of experiments in which initial reaction rates are measured at varying substrate concentrations within the zone of linear p versus t relationship. 

The equation of Michaelis-Menten is hyperbolic as can be easily deduced. From Eq. 3.11  

---