THE DIGESTIVE JUICES 65 



unorganised ferments with the action of which we have chiefly to 

 deal. The unorgcinised ferments may be classified as follows : 



(a) Amylolytic those which change amyloses (starch, glycogen) 

 into sugars. Examples : ptyalin, diastase, amylopsin. 



(b) Proteolytic those which change native proteins into proteoses 

 and peptones. Examples : pepsin, trypsin. 



(c) Steatolytic or lipolytic those which split fats into fatty acids 

 and glycerin. An example, steapsin, is found in pancreatic juice. 



(d) Inversive those which convert saccharoses (cane sugar, 

 maltose, lactose) into glucose. Examples : invertin of intestinal 

 juice and of yeast cells. 



A 



FIG. 14. Bacillus anthracis, the agent that produces anthrax or splenic fever (jloch) : A, bacilli 

 mingled with blood corpuscles from the blood of guinea-pig, some of the bacilli dividing ; B, the 

 same after three hours' culture in a drop of aqueous humour. They grow out into long leptothrix- 

 like filaments, which subsequently divide up, and spores are developed in the segments. 



(e) Coagulative those which convert soluble into insoluble 

 proteins. Examples : rennet, fibrin ferment. 



Most ferment actions are hydrolytic i.e. water is added to the 

 material acted on, which then splits into new materials. This is seen 

 by the following examples : 



1. Conversion of cellulose into carbonic acid and marsh gas 

 (methane) by putrefactive organisms. 



[cellulose] [water] [carbonic [methane] 



acid] 



2. Inversion of cane sugar by the unorganised ferment invertin : 

 C 12 H 22 U +H 2 0=C 6 H 12 6 + C 6 H 12 6 



[cane sugar] [water] [dextrose] [levulose] 



F 



