750 



PHYSIOLOGY OF DIGESTION AND SECRETION. 



made or unmade, that is to say, it constitutes a reversible reac- 

 tion. In a mixture of bile salts and lipase, for example, the bile 

 salts may be removed by dialysis. In activation, on the contrary, 

 we have an irreversible reaction the active trypsin cannot be 

 changed to the inactive trypsinogen.* 



PARTIAL LIST OF THE ENZYMES CONCERNED IN THE PROC- 

 ESSES OF DIGESTION AND NUTRITION. 



ENZYME. 



Ptyalin (sali- 

 vary diastase. 



Amylase (pan- 

 creatic dias- 

 tase). 



Liver glyco- 

 genase. 



Muscle glyco- 

 genase. 



Invertase. 



Maltase. 



Lactase. 

 [Glycolytic? 



WHERE CHIEFLY 

 FOUND. 



Salivary secretion. 



Pancreatic secre- 

 tion. 



Liver. 

 Muscles. 

 Small intestine. 



Small intestine, sali- 

 vary and pancre- 

 atic secretion. 



Small intestine. 



Muscles? 



Pancreatic secre- 

 tion, fat, tissues, 

 blood, etc. 



Gastric juice. 



Pancreatic juice. 

 Small intestine. 



ACTION. 



Converts starch to sugar 

 (maltose). 



Converts starch to sugar 

 (maltose). 



Converts glycogen to dex- 

 trose. 



Converts glycogen to dex- 

 trose. 



Converts cane-sugar to 

 dextrose and levulose. 



Converts maltose to dex- 

 trose. 



Converts lactose to dex- 

 trose and galactose. 



Splits and oxidizes dex- 

 trose. 



Splits neutral fats to fatty 

 acids and glycerin. 



Converts proteins to pep- 

 tones and proteoses. 



Splits proteins into their 

 constituent amino-acids. 



Splits peptones and pro- 

 teoses into their con- 

 stituent amino-acids. 



Splits proteins into nitrog- 

 enous bases and amino- 

 bodies. 



Split nucleic acid with for- 

 mation of purin bases, 

 etc. 



Converts guanin to xan- 

 thin by splitting off an 

 NH2 group as ammonia 

 (NH 3 ). 



Converts adenin to hypo- 

 xanthin by splitting off 

 an NH 2 group as am- 

 monia (NHs). 



Splits off the NH 2 group 

 from the amino-acids 

 with the formation of 

 non-nitrogenous organic 

 acids. 



* Consult Bayliss, "The Nature of Enzyme Action" (series of monographs 

 on Biochemistry), London, 1908. 



Group of auto- 

 lytic enzymes. 



Nucleases. 



Guanase. 



P, i Adenase. 



[ Deaminase? 



Tissues generally. 



Pancreas, spleen, 

 thymus, etc. 



Thymus, adrenals, 

 pancreas. 



Spleen, pancreas, 

 liver. 



Tissues generally. 



