What do you mean by Delta Go reflects the nature of reactants and products? (you mean, the direction of the reaction?)
Delta Go is a means of predicting the direction of a reaction. Both the Delta Go and therefore the direction of the reaction depend on the nature of the reactants and products: the reaction will tend to go in the direction of forming the most stable molecules. The Delta G depends not only on the the nature of the molecules involved, but also the amounts of each that are present at the time in question.