For biochemical reactions, this property refers to the standard transformed enthalpy change for a reaction written in terms of biochemical reactants (sums of species), delta-H'o. delta-G'o = delta-H'o - T delta-S'o Units: kJ/mole (This definition from EcoCyc)
Source:http://www.biopax.org/release/biopax-level2.owl#DELTA-H