Metabolic modeling can suggest which is the key enzyme activity that needs to be controlled or its activity enhanced for the required production of a metabolite in a pathway. It also helps to find possible drug targets (enzymes to be inhibited). In metabolic modeling, knowing the kinetics of the enzymes involved in a pathway is mandatory. Most enzymatic reactions involve multi-substrates and follow an ordered sequential or ping-pong mechanism. The kinetic parameters involved in the model are obtained by fitting experimental data using a model based on the mechanism. The Cleland model has been used for some years. The grouping of parameters, such as dissociation constant and Michaelis-Menten constant, makes the strategy meaningful and hence the Cleland model is still in use. Although other alternate methods, e. g., the King-Altman method, are available, derivation by determinants can be used to derive a rate expression for the sequential or ping-pong mechanism, they are tedious. Hence, a meaningful modification is suggested in this communication for deriving the enzyme mechanism which is based on Thilakavathi et al. (Biotech Lett 28:1889-1894, 2006) to obtain the Cleland model in an easier way. © 2013 Springer Science+Business Media Dordrecht.