PT - JOURNAL ARTICLE AU - Gassan Nazzal TI - The relative values of the turnover number and the dissociation rate constant determine the definition of the Michaelis-constant AID - 10.1101/052514 DP - 2016 Jan 01 TA - bioRxiv PG - 052514 4099 - http://biorxiv.org/content/early/2016/05/11/052514.short 4100 - http://biorxiv.org/content/early/2016/05/11/052514.full AB - The Km value is widely used and defined as a measure of the stabilify of the ES-complex, however, this is true if the first reaction step exists in rapid equilibrium and the reaction is activation controlled. This paper will discuss the theoretical limitation of each case of the quasi-steady-state approximation using the statistical thermodynamic and the diffusion theory to define the Km value.