44 THE AMINO ACIDS 



CH 2 .CH s .CH a .CH a .CH 2 



NH 2 NH 2 



Cadaverine or Pentamethyldiamine 



Arginine, another amino acid, is the mother sub- 

 stance of putrescine. Arginine under suitable condi- 

 tions yields urea and ornithine, thus : 



CH 2 .CH 2 .CH 2 .CH.COOH 



I ' I 



NH NH a = 



NH a 



C< NH, 



Arginine 



NH 2 CH a .CH 2 .CH 2 .CH.COOH 



I I I ' 



C = O + NH 2 NH 2 



NH 2 

 Urea Ornithine 



Ornithine by cleavage of carbon dioxide yields 

 putrescine or tetramethyldiamine. 



CH 2 .CH 2 .CH 2 .CH.COOH CH 2 .CH 2 .CH 2 .CH, 



NH a NH 2 -CO 2 NH 2 NH 2 



Ornithine Putrescine or 



Tetramethyldiamine 



