Answer the following questions concerning carbohydrate digestion and absorption. (a) Where in the digestive tract does carbohydrate digestion occur? What about absorption? (b) What is the major dietary carbohydrate we ingest? (c) Very briefly, what is the structure of that major carbohydrate referred to in part (b)? (d) What can one say about the size of a carbohydrate when it is absorbed by an enterocyte; i.e., is it likely to be a polysaccharide, an oligosaccharide, a disaccharide, or a monosaccharide?

 

 Answer the following questions concerning protein digestion and absorption. (a) Where in the digestive tract does protein digestion occur? What about absorption? (b) How far are proteins broken down before being absorbed? (c) About what fraction of the amino acids absorbed by the digestive system come from ingested protein?

 

 Answer the following questions concerning lipid digestion and absorption. (a) Where in the digestive tract does lipid digestion occur? What about absorption? (b) Briefly compare and contrast the structure and function of micelles and chylomicrons. (c) Chylomicrons eventually arrive in the bloodstream, but via lymphatic vessels. Why don’t chylomicrons (with their lipid nutrients) go directly into the bloodstream at the small intestine instead of entering lacteals, and using the lymphatic system to deliver them to the bloodstream?