PathwayStep909 PathwayStep910 PathwayStep911 PathwayStep912 PathwayStep913 PathwayStep914 PathwayStep916 PathwayStep915 PathwayStep918 PathwayStep917 Digestion of dietary carbohydrate Authored: D'Eustachio, P, 2006-11-03 14:36:07 Carbohydrate is a major component of the human diet, and includes starch (amylose and amylopectin) and disaccharides such as sucrose, lactose, maltose and, in small amounts, trehalose. The digestion of starch begins with the action of amylase enzymes secreted in the saliva and small intestine, which convert it to maltotriose, maltose, limit dextrins, and some glucose. Digestion of the limit dextrins and disaccharides, both dietary and starch-derived, to monosaccharides - glucose, galactose, and fructose - is accomplished by enzymes located on the luminal surfaces of enterocytes lining the microvilli of the small intestine (Semenza et al. 2001). GENE ONTOLOGYGO:0044245 ISBN0079130356 Reactome Database ID Release 43189085 Reactome, http://www.reactome.org ReactomeREACT_9472 Reviewed: Nichols, BL, 2007-01-15 21:51:24 maltotriose + H2O => maltose + D-glucose (sucrase-isomaltase) maltotriose + H2O => maltose + D-glucose (maltase-glucoamylase) maltose + H2O => 2 D-glucose (sucrase-isomaltase) lactose + H2O => D-glucose + D-galactose sucrose + H2O => glucose + fructose trehalose + H2O => 2 D-glucose maltose + H2O => 2 D-glucose (maltase-glucoamylase) Digestion of branched starch (amylopectin) by extracellular amylase Digestion of 1-6 linkages of limit dextrins to yield maltose, maltotriose, longer maltosides, and glucose Digestion of linear starch (amylose) by extracellular amylase