Chemical Changes in Animal Organism. 295 



CH 3 -OCH 



HOOCH 



HCOH 



a-Methyl Glucoside. 



CH 2 -OH 



/2-Methyl Glucoside. 



The former of these (a-glucoside) can be hydrolyzed 

 into methyl alcohol and dextrose by the presence of the 

 enzyme maltase, which is found in malt extract, and causes 

 the hydrolysis maltose into its monosaccharide (see p. 213), 

 whereas the latter (/?- compound) is not hydrolyzed by the 

 action of maltase, but is hydrolyzed by that of emulsin, 

 an enzyme present in bitter almonds and other plants. 

 Although these two glucosides differ only slightly in their 

 stereochemical configuration, they are acted upon by two 

 different enzymes ; the enzyme which will bring about the 

 hydrolysis of one form will not cause that of the latter. 

 The stereochemical configuration is an important factor to 

 be taken into account when studying the action of the 

 various ferments, and for this reason it has been discussed 

 somewhat fully in this book. 



Other interesting examples of the specificity of ferment 

 action are afforded by the study of the action of the 

 proteoclastic ferments on the polypeptides which have 

 been obtained synthetically. It may be recalled that pro- 

 teins are essentially polypeptides formed by the conjuga- 

 tion of various amino-aculs. E, Fischer and his pupils 



