32 BACTERIAL ENZYMES 



Coenzyme II 



Coenzyme II has a structure similar to that of coenzyme I, 

 with an additional phosphate group in the molecule; the 

 position of the third phosphate in the molecule is not yet 

 certain. The coenzyme acts as hydrogen acceptor towards 

 certain dehydrogenase systems in a manner analogous to 

 that of coenzyme I. 



Adenylic acid, Adenosine-diphosphate, Adenosine-tri-phosphate 



K. r MW i OH OH OH 



N=C-NH2 I I I I 



II Q l_p_0-p-o-P-OH 



HC C-N<^ I ]J I I 



" '^^ -n. CH,0-P-OH I O O O 



N- C-N 



/ 





OH 



H H 



OH OH 



I I 

 -P-O-P-OH 



II II 



Adenosine-tri-phosphate (ATP) acts as a donator of phosphate 

 in phosphorylation reactions such as those that occur in 

 fermentation cycles (see Chap. VII). The phosphate is linked 

 in ATP by an energy-rich bond so that its rupture gives rise 

 to the liberation of energy. Adenylic acid and adenosine-di- 

 phosphate can act as phosphate acceptors, being synthesised 

 to ATP. Since the glycolysis cycle depends upon phosphoryla- 

 tion and dephosphorylation (see Chap. VII) ATP and adenylic 

 acid act as coenzymes in the cycle. 



Adenine-riboflavin-dinucleotide , Flavine-adenine-dinucleotide 



