sucrase, any member of a group of enzymes present in yeast and in the intestinal mucosa of animals that catalyze the hydrolysis of cane sugar, or sucrose, to the simple sugars glucose and fructose.
Granules of sucrase localize in the brush border (a chemical barrier through which food is absorbed) that coats the intestinal villi. If sucrase is absent from the body there is intolerance to sucrose, and other sugars (maltose or lactose) must be substituted for sucrose in the diet to provide adequate nutrition.