PRIMING REACTIONS 195 



But the above are all variants operating during the anaerobic state. In the 

 presence of oxygen , pyruvate un dergoes the same fate in all the different organ- 

 is ms. It undergoes oxidative decarboxylation with productionoface^y /-Co^ 



Glycogen 



) I glucose-6-phospliatase P 



hexokinase 



Glucose 



ADP 

 ATP 



G— 6— P 



phosphorylate 

 G— 1— P 



phosphogtucoisomerasc 



phosphoglucomutase 



phosphohexokinase 

 Mg" 



F— 6— P 



ADP\\ 

 AT? J) 



d iphosphof mctosephosphatase 



F_l.6— PP 



aldolase 

 Phosphodihydroxyacetone ^ 3-Phosphoglyceraldehyde 



triosephosphate 

 dehydrogenase 



It °™' ))h.po. ) 



♦ '^^ DPNH / / * 



/ 



/ 



/ 



/ 



1, 3-diphosphoglyceric acid 



/ 



/ 



ADP 

 ATP 



j I phosphoglyeerate-kinaie 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



/ 



3-phosphoglyceric acid 



2-phosphoglyceric acid 



phosphoenolpyruic acid 



phosphoglyceromutai* 



enolasc 



L-lactic acid 



—► DPNH 

 DPN 



" )) 



N- // 



lactic dehydrogenase 



alcohol dehydrogenase 



ADP 

 ATP 



)) 



Ethanol 



pyruvic acid 

 ^ 



Acetaldehyde 



pyruvate-kinas* 



carboxylase 

 Mg" 



Fig. 40 — Scheme to summarize reactions of glycolysis. The entry of glucose and glycogen 



is shown. For other entries see Fig. 37. Two terminations are shown : that of alcoholic 



fermentation and that of lactic fermentation. 



