CLASSIFICATION OF ENZYMES 179 



number of the enzymes of this class causes this rearrange- 

 ment, splitting the molecule without the addition to or sub- 

 traction from any elements therein. 



3. Oxidizing, the addition of oxygen to (or the subtrac- 

 tion of hydrogen from) the molecule of the substance acted 

 upon. 



4. Reducing, the subtraction of oxygen from (or the 

 addition of hydrogen to) the molecule of the substance 

 acted upon. The reducing enzymes are the only class of 

 enzymes in the above classification acting upon inorganic 

 compounds; some organic compounds are also acted upon, 

 viz., litmus, methylen blue, etc. 



5. Coagulating, unknown processes accompanied by 

 coagulation. Enzymes whose actions are not so well known 

 are those producing syntheses, isomers, acting anaerobically, 

 etc. 



Note. Euler's suggestion that the names of enzymes be formed from 

 the compound acted upon, by suffixing "-ase," will be adhered to in all 

 subsequent study of enzymes, the suffix u -lytic " for the adjective, and the 

 suffix "-ese " for synthesizing enzymes. 



Bayliss has suggested the ending "-clastic" for the adjective, criticiz- 

 ing the ending '-lytic" because the definition of electrolytic," which 

 must be granted priority, implies action by the agent rather than upon 

 the substance indicated by the term. He also questions the existence of 

 Euler's "synthesizing enzymes," 



CLASSIFICATION OF ENZYMES 



I. Hydrolytic Enzymes of: 



A. Carbohydrates, including Glucosides, carbohydrases 



general term. 

 1. Polysaccharides. (CeHioOs)^. 



a. Celluloses: cellulases general term. 

 b' Hemicelluloses : cytases general term. 



c. Starches, insoluble and soluble: amylases, 



(ptyalin, diastase) general term. 



d. Glycogens: glycogenases general term. 



e. Dextrins: dextrinases general term. 



