What is The rate of absorption of sugars by the small intestine is highest for: and explain in detail?
Hexose absorption is twice as fast as pentose absorption. The absorption rate of hexoses in intestine is : Galactose> Glucose > Fructose. Glucose & Galactose are absorbed by SGLT-1 (Sodium dependent glucose transpo), against the concentration gradient (active transpo). But Fructose is absorbed by GLUT-5, along the concentration gradient (passive transpo). (remember passive transpo is much slower as compared to active transpo) All the monosaccharides exit from intestinal cells into blood GLUT-2. Disaccharides and polysaccharides are broken down to their respective monosaccharides before absorption.