In this work, the binding of coenzymes to yeast alcohol dehydrogenase (EC 1.1.1.1) were investigated. The main criterions were the change in the standard free energies for individual reaction steps, the internal equilibrium constants and the overall changes in the reaction free energies. The calculations were performed for the wild type enzyme at pH 6-9 and for 15 different mutant type enzymes, with single or double point mutations, at pH 7.3. The abundance of theoretical and experimental data enabled the binding of coenzymes to enzyme to be assessed in depth.