DIGESTION 

 CHIEF DECOMPOSITION PRODUCTS OF PROTEINS. 



MONOAMINO-ACIDS AND THEIR COMPOUNDS. 



/Glycin or glycocoll (aminoacetic acid), CH 2 (NH 2 )COOH. 

 Alanin (aminopropionic acid), CH 3 CH(NH 2 )COOH. 

 Serin or oxyalanin (oxyaminopropionic acid), 



CH 2 OH.CH(NH 2 ).COOH. 



Valin or aminovalerianic acid, ^ 3 / CHCH ( NH 2) COOH - 



Leucin (a-aminoisobutylacetic acid) ^ 3 ^)CHCH 2 CH(NH 2 )COOH. 



Norleucin (-amino-caproic acid), 



CH 3 .CH 2 .CH 2 .CH 2 .CH(NH 2 ).COOH. 

 Isoleucin (a-amino-/3-methyl-/3-ethyl-propionic acid), 



rH \ 

 ^ 3 ^>CH.CH(NH 2 ).COOH. 



Cystein (a - amino-/3 - thiopropionic acid), CH 2 (SH).CH(NH 2 )COOH, 

 which is unstable, two molecules of it easily yielding cystin 

 di-(n-amino-/3-thiopropionic acid) , 



COOH.CH(NH 2 ).CHa.S.S.CH 2 .CH(NHj).COOH. 



fAspartic or aminosuccinic acid, CH(NH 2 ).COOH. 



Jen I 

 CH 2 COOH. 



Q rt I Glutamic or glutaminic acid, C 



*~ <n 

 4j O <O 



S "S - fTyrosin (para-oxyphenylaminopropionic acid), 



CgH 4 OH .CH 2 .CH(NH 2 ) .COOH . 

 8'C [Phenylalanin (phenylamjnopropionic acid), C 6 H 5 CH 2 CH(NH 2 )COOH. 



m oj 4> 



a -si 



Prolin (pyrrolidin carboxylic acid). 

 Oxyprolin (oxypyrrolidin carboxylic acid). 

 Tryptophane (a-amino-j3-indol-propionic acid), 



yNH CH 



\N C CH 2 .CH(NH a ).COOH. 

 Histidin (/J-imidazol-a-aminopropionic acid), C 6 H 9 N 3 O 2 . 



DlAMINO-ACIDS AND THEIR COMPOUNDS. 



Lysin (a-amino--amino-caproic acid, CH 2 NH 2 (CH 8 ) 3 CH(NH 2 )COOH. 

 Arginin (guanidinaminovalerianic acid), 



ufa p/ NH 2 



\NH CH 2 (CH 2 ) 2 CH (NH 2 ) COOH . 



Ammonia (representing the so-called ' amide-nitrogen,' and liberated 

 from the products of acid hydrolysis of proteins by heating the 

 mixture after addition of alkali). It has not been shown that 

 ammonia is itself one of the ' Bansteine ' of the proteins. 



