GENERAL PRINCIPLES OF BIOCHEMICAL ENERGETICS 



143 



thioester bond is transferred to the acyl-phosphate bond. 1,3-diphos- 

 phoglyceric acid subsequently detaches itself from the protein molecule. 



.O 



\ 



— H,0 



OH 



CHOPO(OH), 



CH.OH 



2-phosphoglyceric acid 





OH 



CO-PO(OH); 



CH, 



phosphoenolpyruvic acid 



— » 



o 



OH 



^ 



O 



OH 



CO--PO(OH), +ADP ^ COH -f- ATP 



CH2 



phosphoenolpyruvic acid 



CH, 



pyruvic acid (enolic form) 



^ 



-^ 



V 



o 



OH 



c-=o 



CH3 



pyruvic acid (ketonic form) 



This reaction can only continue till all the substrate is used up, if the 

 reaction product, which is 1,3-diphosphoglyceric acid, is removed 

 from the solution ; in the cell, this acid then reacts with ADP, converting 

 it into ATP; the energy-rich anhydride bond then disappears 



