No it could not serve the same function, because its formation is too endergonic (+11.8 kcal/mol), which is the reason that it can be used to form ATP by substrate-level phosphorylation (i.e., its phosphate transfer potential is much higher than that of ATP). Solution No it could not serve the same function, because its formation is too endergonic (+11.8 kcal/mol), which is the reason that it can be used to form ATP by substrate-level phosphorylation (i.e., its phosphate transfer potential is much higher than that of ATP)..