The Columnar Epithelial Cell of the Small Intestine: Digestion and Transport

Cellular Digestion Carbohydrates In the western diet, carbohydrates are ingested almost entirely in the form of starch and the disaccharides, sucrose and lactose; free glucose accounts for less than 3 per cent of ingested carbohydrate.²⁰⁴ Pancreatic amylase initially attacks α-1,4 glycosidic bonds in the interior of starch molecules, producing oligosaccharides, which it hydrolyzes slowly to maltose and maltotriose.²⁰⁵ The α-1,6 branch points are not attacked, and “limit dextrins” of various sizes, containing glucose molecules surrounding α-1,6 branch points, remain. Pancreatic amylase is found not only in the intestinal lumen but also adsorbed to the lining epithelium,²⁰⁶,²⁰⁷ and under some conditions.