A Model Metabolic Cycle Simulated with the Mathematica Program

Abstract

A system of differential equations has been used to simulate a model metabolic cycle, containing only one initial substrate and 8 irreversible enzymes. The metabolic course of the intermediates (products/substrates) was also explored in different situations: changes in the kinetic constants of one of the enzymes of the cycle; introduction of one reversible step; consecutive increments in the Km values of each enzyme of the cycle and the presence of two initial substrates. A decrease or an increase in the Km value of one of the enzymes of the cycle promotes a decrease or an increase in the steady state level of its own substrate, respectively; by the contrary, a decrease or an increase in the Vmax value promotes, respectively, an increase or a decrease in the stationary level of the corresponding substrate. A comparison between a linear and a cyclic metabolic pathway is also presented.