6.1 Digestion and Absorption

Understandings

U1. The contraction of circular and longitudinal muscle layers of the small intestines mixes the food with enzymes and moves it along the gut. contraction of longitudinal muscles moves the food forward along the gut.

U2.The pancreas secretes enzymes into the lumen of the small intestines.

PANCREATIC JUICES hydrolyze (add water break apart) the following larger molecules: ENZYME SUBSTRATE PRODUCT LIPASE lipids or TRIGLYCERIDES fatty acids and glycerol or monoglycerides AMYLASE starch (amylose) maltose PHOSPHOLIPASE phospholipids fatty acids, glycerol , and a phosphate group PROTEASE proteins and polypeptides shorter peptides.

U3. Enzymes digest most macromolecules in food into monomers in the small intestines.

PANCREATIC JUICE complete digestion and hydrolyze into monomers or single units. ENZYME SUBSTRATE PRODUCT NUCLEASE DNA and RNA nucleic acids NUCLIOTIDES MALTASE MALTOSE GLUCOSE and GLUCOSE LACTASE LACTOSE GLUCOSE and GALACTOSE SUCRASE SUCROSE GLUCOSE and FRUCTOSE DIPEPTIDASE DIPEPTIDES AMINO ACIDS EXOPEPTIDASE POLYPEPTIDES

U4. Villi absorb monomers absorbed by digestion as well as mineral ions and vitamins.

U5. Villi increase the surface area in epithelium over which absorption is carried out.

U6. Different methods of membrane transport are required to absorb different nutrients.

GLUCOSE TRANSPORT

Applications

Processes occurring in the small intestine that result in the digestion of starch and transport of the products of digestion to the liver. MALTOSE digested by MALTASE MALTOTRIOS- digested by GLUCOSIDASE DEXTRIN- digested by DEXTRINASE *** All digested into GLUCOSE monomers by these enzymes in the microvilli of SI

Use of dialysis tubing to model absorption of digested food in the intestines. (Nature of Science- models are representations of the real world)

Skills

Production of an annotated diagram of the digestive system.

Identification of tissue layers in transverse sections of the small intestines viewed with a microscope or in a micrograph.