ABSTRACT
Metabolism is the collection of chemical interconversions carried out by living organisms as they feed, grow and reproduce. It is the overall sum of several thousand individual chemical reactions brought about by catalytic proteins called enzymes. This set of reactions forms a highly branched network in which the cross-connections are increased because the majority of reactions involve at least two reactants. Although each enzyme reaction consists of a number of elementary steps obeying linear chemical kinetics, its overall kinetic behaviour is nonlinear in the concentration of the chemical intermediates of the metabolic net. Thus a possible description of the dynamics of the network is as a system of nonlinear ordinary differential equations, though severe practical problems confront attempts to model even small parts of the metabolic net.
