62 BACTERIOLOGICAL AiSD EiSTZYME CHEMISTRY 



Upon hydrolysis, according to the general reaction several 

 times referred to, a salt of lactic acid is formed thus : — 



CH3 CH, 



1 ] 



CHOH + KOH = CHOH + NH3 + H^O 



CN COOK 



This acid contains, it will be seen, the group CHOH ; upon 



oxidation, therefore, this will yield the group =C=0, and a 

 ketonic acid is formed, thus : — 



CH3 CH3 



1 I 



CHOH + = C=0 + H2O 



I I 



COOH COOH 



It should here be noted that it is customary for the con- 

 venient nomenclature of open chain compounds to refer to the 

 C atoms ia order as a, y3, 7, etc., according as they are one, 

 two, three, etc., removes from the end of the chain. The above 

 lactic acid is therefore known as a lactic acid. It is obvious 

 that the hydroxyl OH group might be attached to the second 

 carbon atom, when a /S acid would be obtained. We thus have : 



CH3 CH2OH 



(a) CHOH (yS) CH, 



I I " 



COgH CO2H 



As a matter of fact the latter is the second lactic acid 

 above referred to. It is obtained fi'om fi iodopropionic acid, 

 which is known to have the constitutional formula 



