Fig. 1.
Differential isotopic 18O/16O substitutions in ATP molecule phosphoryls (a). Oxygen tags: αb – alpha bridge, αp – alpha peripheral, βb – beta bridge, βp – beta peripheral, γb - gamma bridge, γp – gamma peripheral. Enzymatic reactions involved in 18O enrichment of ATP α-, β- and γ-phosphoryls (b). FFA - free fatty acids; AA - amino acids; PDE- phosphodiesterase.