4 PHYSIOLOGICAL CHEMISTRY 



has very recently shown that "the rabbit does not form a protective 

 ferment in response to the injection of the protamine of the salmon. " 

 He, however, points out the fact that this does not prove that a de- 

 fensive enzyme is not formed in response to the passage of placental 

 protein into the blood. 



Our knowledge regarding the distribution of enzymes has been 

 wonderfully broadened in recent years. Up to within a few years, 

 the real scientific information as to the enzymes of the animal organism, 

 for example, was limited, in the main, to a rather crude understanding 

 of the enzymes intimately connected with the main digestive func- 

 tions of the organism. We now have occasion to believe that enzymes 

 are doubtless present in every animal cell and are actively associated 

 with all vital phenomena. As a preeminent example of such cellular 

 activity may be cited the liver cell with its reputed complement of 15-20 

 or more enzymes. 



A list of the more important enzymes together with their class, dis- 

 tribution, substrate and end-products is given below. 



CLASSIFICATION OF ENZYMES 



Deaminases- 



Amino compounds I 



4. Urease. 



Micrococcus 

 bean, etc. 



ureae, soy \ Urea. 



I Carbon dioxide and am- 

 monia. 



Glucosidases jGlucosides (amygdalin andi 



others). 



1. Emulsin Plants '/3-glucosides {Glucose, etc. 



2. Invertase Yeast, etc a-glucosides Glucose, etc. 



