Overview Absorption of carbohydrates intestinal epithelial cells in small intestine (enterocytes) absorb only monosaccharides glucose, galactose, and fructose Glucose & Galactose glucose and galactose are absorbed across apical membrane of enterocytes bysecondary active transport glucose and galactose move from intestinal lumen into enterocytes via Na+- glucose cotransporter (SGLT1) SGLT in apical membrane of enterocytes glucose and galactose move up (or against) electrochemical gradient ("uphill") Na+ moves down electrochemical gradient ("downhill") provides energy for uphill movement of glucose and galactose Na+-K+ ATPase in basolateral membrane of enterocytes establishes and maintains Na+ gradient across apical membrane responsible for providing energy for uphill movement of glucose and galactose glucose and galactose move from enterocytes across basolateral membrane to bloodstream by facilitated diffusion (GLUT2) Fructose fructose is absorbed across apical membrane of enterocytes by facilitated diffusion (GLUT5) unlike glucose and galactose, fructose cannot be absorbed against electrochemical gradient ("uphill") fructose moves from enterocytes across basolateral membrane to bloodstream byfacilitated diffusion (GLUT2)