In: Anatomy and Physiology
Carbohydrate digestion begins when the complex carbohydrate starch is broken down into maltose. Which enzymes catalyze the breakdown of maltose into monosaccharides, and where are the enzymes found?
a)Carbohydrases located throughout the intestines
b)Pancreatic amylase released by the pancreas
c)GLUT2 located on the basolateral surface
d)Disaccharidases located at the intestinal brush border
Disaccharidases located at the intestinal brush border, catalyze the breakdown of maltose into monosaccharides.
These enzymes are glycoside hydrolases which catalyzes the hydrolysis of glycosidic bonds in complex sugars and convert them into simple sugars for absorption.
Examples of disaccharidases are :
Lactase ( breaks down lactose into glucose and galactose )
Maltase ( breaks down maltose into two molecules of glucose )
Sucrase ( breaks down sucrose into glucose and fructose )
Trehalase ( breaks down trehalose into two glucose )
A genetic defect in lactase causes lactose intolerance and in sucrase causes sucrose intolerance.
Carbohydrases breaks down complex sugars like starch into simpler sugar. Example : amylase which breaks down starch into maltose.
Pancreatic amylase coverts dietary starch into disaccharides and trisaccharides.
GLUT 2 ( Glucose transporter 2 ) is a transmembrane carrier protein that enables protein facilitated glucose movement across the cell membrane. It is the main transporter of glucose between liver and blood.