Digestion and absorption of carbohydrates

Mouth and stomach

Salivary gland, pancreas and small intestine

Produces amylase that HYDROLYSES the GLYCOSIDIC bonds in starch into maltose

Produces pancreatic amylase that also hydrolyses glycosidic bonds in starch to produce maltose

Digesting all the starch in the mouth with amylase would take too long so it is also digested in the pancreas as well

Contains 3 membrane bound disaccharidases (Maltase, sucrase and lactase) Hydrolyses respective disaccharides into monosaccharides e,g Maltase hydrolyses maltose into glucose etc.

Co-transport with sodium ions into the epithelial cell and then facilitated diffusion into the capillaries

Facilitated diffusion into capillary by a different transport protein

1) Glucose moves into epithelial cells by facilitated diffusion until equilibrium 2) After equilibrium, glucose is co-transported with sodium ions into the epithelial cell and the energy is given mainly by the concentration difference of sodium ions 3) After entering the epithelial cells the glucose molecules diffuse into the capillaries by facilitated diffusion

The sodium potassium pump is in the epithelial cell and constantly pumps sodium ions into the capillaries out of the epithelial cells to give the epithelial cell a low concentration of sodium ions. This is because sodium ions need to co-transport glucose and amino acids into the epithelial cell. The pump requires ATP

Long - Large SA Folded - Large SA Villi - Large SA Thin epithelium (inner layer - Short diffusion pathway one cell thick Micro villi - Large SA Mitochondria - ATP for active transport of sodium ions and ATP for Na/K pump Good blood supply - Maintain concentration gradient