THE MONO-AMINO-ACIDS. 83 



acids occurs into the ammonium salts of the fatty acids standing 

 next in order in the downward scale, and that by further oxidation 

 these are transformed into ammonium carbonate, and this into urea. 

 It has been shown as a matter of fact that a fair amount of urea is 

 produced when blood containing ammonium carbonate or ammonium 

 formate is allowed to flow through the isolated livers of dogs. 



According to Drechsel, the amino-acids are transformed into 

 carbamic acid, from which urea may then result, as indicated by the 

 equation : 



,XHi NH 2 



co + co 



On the other hand, it is conceivable that the amino-group merely 

 is split oif and leads to the formation of urea, and that the remain- 

 ing fatty acid radicles may be utilized in the synthesis of carbo- 

 hydrates and fats. 



In a subsequent chapter this subject will be treated in greater detail. 



In addition to the important role which the amino-acids play 

 in the formation of urea, they are of further interest from the part 

 which they take in some of the syntheses that occur in the animal 

 organism. With benzoic acid glycocoll thus combines to form hip- 

 puric acid, as shown by the equation : 



CH 2 (NH 2 ).COOH + C 6 H 5 .COOH = CH 2 .NH(C 6 H 5 CO).COOH + H 2 O 

 Glycocoll. Benzoic acid. Hippuric acid. 



With phenyl-acetic acid glycocoll similarly combines to form 

 phenaceturic acid : 



CH 2 .(NH 2 ).COOH + CH 2 .(C 6 H 5 ).COOH = 



C 6 H 5 .CH 2 .CO NH.CH 2 .COOH + H 2 O. 



That uric acid on hydrolytic decomposition will yield ammonia, 

 carbon dioxide, and glycocoll has been shown. There is evidence, 

 moreover, to show that in the organism of birds and reptiles, at 

 least, its synthesis can similarly occur. 



Ornithuric acid results through the union of benzoic acid with the 

 diamine ornithin : 



C 4 H 7 (NH 2 ) 2 .COOH -f 2C 6 H 5 .COOH = C 4 H 7 (NH.C 6 H 5 .CO) 2 .COOH + 2H 2 O 

 Ornithin. Benzoic acid. Ornithuric acid. 



The amino-acids also are closely related to the biliary acids, as on 

 decomposition with baryta-water, glycocholic acid is decomposed 

 into glycocoll and cholalic acid, as shown in the equation : 



C^H^NOe + H 2 = CH 2 (NH 2 ).COOH + C 24 H 40 O 5 

 Glycocholic Glycocoll. Cholalic 



acid. acid. 



Taurocholic acid similarly gives rise to cholalic acid and taurin, 

 which latter can be regarded as am ino-iseth ionic acid that is, as 



