6.1 Digestion + Absorption
Topic 6: Human physiology 20 Hours
Digestion and absorption
6.1.1 The structure of the wall of the small intestine allows it to move, digest and absorb food.
Nature of science:
6.1.2 Use models as representations of the real world—dialysis tubing can be used to model absorption in the intestine. (1.10)
6.1.3 The contraction of circular and longitudinal muscle of the small intestine
mixes the food with enzymes and moves it along the gut.
6.1.4 The pancreas secretes enzymes into the lumen of the small intestine.
6.1.5 Enzymes digest most macromolecules in food into monomers in the small
6.1.6 Villi increase the surface area of epithelium over which absorption is carried out.
6.1.7 Villi absorb monomers formed by digestion as well as mineral ions and
6.1.8 Different methods of membrane transport are required to absorb different nutrients.
6.1.9 Application: Processes occurring in the small intestine that result in the
digestion of starch and transport of the products of digestion to the liver.
6.1.10 Application: Use of dialysis tubing to model absorption of digested food in the intestine.
6.1.11 Skill: Production of an annotated diagram of the digestive system.
6.1.12 Skill: Identification of tissue layers in transverse sections of the small intestine viewed with a microscope or in a micrograph.
6.1.13 Students should know that amylase, lipase and an endopeptidase are
secreted by the pancreas. The name trypsin and the method used to activate
it are not required.
6.1.14 Students should know that starch, glycogen, lipids and nucleic acids are
digested into monomers and that cellulose remains undigested.
6.1.15 Tissue layers should include longitudinal and circular muscles, mucosa and epithelium.
6.1.16 Some hydrolytic enzymes have economic importance, for example amylase in production of sugars from starch and in the brewing of beer.
6.1.17 Syllabus and cross-curricular links:
Topic 2.1 Molecules to metabolism
Topic 2.5 Enzymes
Lesson Name: 6.1 Digestion + Absorption