ENEKGY SUPPLY OF THE CELL 59 



Another very common type of decomposition of amino 

 acids is decarboxylation, i.e., the splitting off of the CO2 

 group. This is the way in which amins are formed. 

 E.g., glycine is decomposed into methyl amin by Ps. 

 fluorescens (Emmerling and Reiser, 1902). 



CH2(NH2)COOH = CH3NH2 + CO2 



In this same way, cadaverin may be produced from lysin. 



CH2(NH2)-CH2-CH2-CH2-CH(NH2)-COOH = 



Lysin 



CH2(NH2)-CH2CH2-CH2CH2-NH2 + CO2 



Cadaverin 



Putrescin, or tetra methylene diamine, probably origi- 

 nates from arginine in a similar way. 



Quite often, decarboxylation and deaminization occur 

 simultaneously. Examples of this have been shown 

 already (p. 43) in the decomposition of leucin, isoleucin, 

 tryptophane and tyrosin by yeast. 



Aside from these decompositions of amino acids, 

 which can be grouped into distinct classes, many other 

 changes may occur which are typical for one certain 

 amino acid only. This is especially true with oxidative 

 changes. Hydrolysis of amino acids will yield hydroxy 

 acids, and these may be used as substrates for anaerobic 

 fermentations (p. 76). 



Another group of protein cleavage products are the 

 acid amids. The energy yield of their hydrolysis is 

 probably quite considerable as will be shown later 

 (see p. 77). 



Anaerobic Putrefaction. — It has been generally assumed 

 that anaerobic putrefaction of proteins as we find it 

 most pronounced in the group of the anaerobic spore 

 formers, follows essentially the same type that has 



