Abstract
The heat of the reaction NAD++propan-2-ol=NADH+acetone+H+ was determined to be 42.5±0.6kJ/mol (10.17±0.15kcal/mol) from equilibrium measurements at 9–42°C catalysed by yeast alcohol dehydrogenase. With the aid of thermochemical data for acetone and propan-2-ol the values of ΔH=−29.2kJ/mol (−6.99kcal/mol) and ΔG0=22.1kJ/mol (5.28kcal/mol) are derived for the reduction of NAD (NAD++H2=NADH+H+). These values are consistent with analogous but less accurate data for the ethanol–acetaldehyde reaction. Thermodynamic data for the reduction of NAD and NADP are summarized.