Beilstein-Institut Thermodynamic Property Values for Enzyme-catalyzed Reactions

This chapter deals with how one can obtain values of thermodynamic properties – specifically the apparent equilibrium constant K’, the stan-dard molar transformed Gibbs energy change DrG’, and the standard molar transformed enthalpy change DrH’ for biochemical reactions – and, in particular, for enzyme-catalyzed reactions. In addition to direct measurement, these property values can be obtained in a variety of ways: from thermochemical cycle calculations; from tables of standard molar formation properties; by estimation from property values for a chemically similar reaction or substance; by means of estimation by using a group-contribution method; by combining a known value of the standard molar enthalpy change DrH and an estimated value for the standard molar entropy change DrS in order to obtain the standard molar Gibbs energy change DrG for a given reaction; and by use of computational chemistry