Introduction
Since real samples contain many substrates, competitive reactions among these substrates for the same or different binding sites on proteins, receptors and so on is a common occurrence in biological samples. For example, several substrates could competitively bind to an enzyme with a single binding site. Utilizing strictly a kinetic approach to model these types of competitive reactions is not possible since the mathematical models either cannot be integrated or the solutions are too complex to be of practical value. To derive equations for a competitive model, we will assume that all the binding reactions are at equilibrium. This assumption places restrictions on the experimental conditions and thus, it is imperative that the model be understood before experimental data is collected. We will first review reversible binding reactions for a single substrate binding to a single binding site. We will expand this model to two different substrates binding to a single binding site and to multiple binding sites....