In this sub-unit we are going to explain the concepts of:

• The contraction of circular and longitudinal muscle of the small intestine mixes the food with enzymes and moves it along the gut

• Enzymes digest most macromolecules in food into monomers in the small intestine
• The pancreas secretes enzymes into the lumen of the small intestine
• Villi increases the surface area of epithelium over which absorption is carried out
• Villi absorb monomers formed by digestion as well as mineral ions and vitamins
• Different methods of membrane transport are required to absorb different nutrients