6.1 Digestion and absorption

IB Syllabus Statements

Understandings:

The contraction of circular and longitudinal muscle of the small intestine mixes the food with enzymes and moves it along the gut.
The pancreas secretes enzymes into the lumen of the small intestine.
Enzymes digest most macromolecules in food into monomers in the small intestine.
Villi increase 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.

Applications and skills:

Application: Processes occurring in the small intestine that result in the digestion of starch and transport of the products of digestion to the liver.
Application: Use of dialysis tubing to model absorption of digested food in the intestine.
Skill: Production of an annotated diagram of the digestive system.
Skill: Identification of tissue layers in transverse sections of the small intestine viewed with a microscope or in a micrograph.

What is an example model of intestine absorption in the real world?
Explain how the small intestine moves food along the gut.
Explain the role of the pancreas and the three enzymes it secretes.
What is the importance of increased surface area by villi?
What do villi absorb?
What gets digested into monomers, and what remains undigested?
Outline different methods of membrane transport relevant to absorption of nutrients in the small intestine.
Outline processes that occur in the small intestine that result in the digestion of starch and transport of the products to the liver.
Explain the use of dialysis tubing as a model for absorption in the intestine.
What economic importance do some hydrolytic enzymes have?
Explain how you would draw a diagram of the digestive system, including the relative locations of the organs.
Explain how you would identify tissue layers in transverse sections of the small intestine when viewed through a microscope or on a micrograph.