The New Student's Reference Work/Enzymes

En′zymes (often called soluble ferments), substances of unknown but very complex composition produced in plants and animals for digesting insoluble foods or those which cannot be used readily without such change. The changes they produce are of two sorts: (1) the commoner consists in causing the food to take into its composition an additional molecule of water; (2) without any additions it may be split up into two or more compounds. Enzyme itself does not take part in the chemical reaction, but seems to act only by its presence. Consequently a very small amount of an enzyme may digest large quantities of a food. Each enzyme is restricted in its action to a particular substance. Some of the more important enzymes, the substance on which they act and the chief products are shown in the following table:

ENZYME	SUBS. ON  WHICH IT ACTS	PRODUCT
Diastase	Starch	Malt-Sugar
Ptyalin	Starch	A sugar
Cytase	Cellulose	A sugar
Invertase	Cane-Sugar	Grape-Sugar and  Fruit-Sugar =  “invert sugar”
Maltase	Malt-Sugar	Grape-Sugar
Imulase	Inulin	Fruit-Sugar
Emulsin	Glucosides	Glucose, etc.
Pepsin	Proteids	Peptones
Trypsia	Proteids	Amides
Lipase	Fats	Glycerin, fatty acids
Zymase	Sugars	Alcohol, carbon dioxid