CHAPTER VI 



AMINO-ACIDS, PROTEINS, UREA AND 



URIC ACID 



AMINO-ACIDS 



The amino compounds and derivatives which we have thus 

 far considered have been first the alkyl- amines in which an 

 alkyl group {e.g.) methyl, ethyl, propyl, etc., has been substi- 

 tuted in ammonia for one hydrogen yielding a substituted 

 ammonia compound. These show a close relationship to 

 ammonia in many of their reactions, especially the formation 

 of ammonium-like salts. The compounds are also to be con- 

 sidered as amino substitution products of the hydrocarbons in 

 which the amino radical NH2 is substituted for one hydrogen in 

 a hydrocarbon. Methyl amine is also, therefore, amino-methane. 



H 



/CH3 I 



N^H or H-C-NH2 



\h I 



H 



Methyl amine Amino-methane 



As amino substituted hydrocarbons, the amines are thus exactly 

 analogous to the halogen and hydroxy substitution products. 



CH3 - CI CH3 - OH CH3 - NH2 



Mono-chlor-methane Hydroxy-methane Amino-methane 



In connection with the derivatives of acids we considered 

 also the acid amides in which the hydroxyl portion of the car- 

 boxyl group was replaced by the amino group. 



CH3 - COOH -> CH3 - CONH2 



Acetic acid Acet-amide 



Now just as we have mixed compounds which contain both 

 halogen and carboxyl or both hydroxyl and carboxyl groups, 



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