86 A. I. RINGER 



7. Normal Leucin or a-amino caproic acid. 

 CH 3 



6-CH 2 

 Y-CH 2 

 P-CH 2 



COOH 



These amino acids are neutral in reaction, but have the property of 

 uniting with both acids and alkali. Glycocoll, for example, can combine 

 with NaOH forming sodium glycocollate: 



CH 2 NH 2 CH 2 NH 2 



" NaOH - * + H 2 O 



COONa 



Sodium So.dium Glycocollate 

 hydroxid 



which is still capable of combining with an acid radical, because of the 

 free basic amino radical ( NH 2 ). 



On the other hand, glycocoll can combine with an acid like hydrochloric, 

 forming a well defined salt, glycocoll hydrochlorid, which is acid in re- 

 action. 



CH 2 NH 2 CH 2 NH 3 C1 



+ HC1 - 



COOH COOH 



Glycocoll Hydrochloric Glycocoll hydrochlorid 



acid 



and is capable of uniting with alkali because of its free acid radical 

 ( COOH) known as carboxyl. 



B. Dibasic Mono Amino Acids. 



1. Aspartic acid or a-amino succinic acid. 

 COOH 



P-CH 2 

 a-CHNH 2 

 COOH 



