THE PKOTEJXS AND THEIR METABOLISM 87 



2. Glutamie acid or a-ainino glutaric acid, 

 COOH 



COO1I 



Those amino acids arc strongly acid in reaction because of the fact 

 that th'-y possess two acid radicals and only unc base. Jn spite of the fact 

 ;!iat they are strongly acid, they possess the power of combining with other 

 ai'ids. f'.rming salts. 



COOH COOH 



I I 



Clio CHo 



I + HC1 -> | 

 CIIXIL, CIJXII.Cl 



! I 



COOH COOH 



Aspartic acid Aspartic acid 



hydrochlorid 



Tlif-y also have the power of combining with two alkali radicals be- 

 ausL 1 of the two carboxyl ( COOH) radicals. 



COOH COOXa 



I ! 



cii 2 en, 



+ 2XaOII -^ | -r 2H a O 



CHXIL CHXIIo 



COOH COOXa 



C. Ily.lroxy- and Thio-a-amino acids. 



1. Serin or a-amino P-hydroxypropionic acid. 



-CIIXH 2 



i 



COOH 



