6.1 Digestion

Starch digestion in the small intestine Illustrates many processes that we have learned about Membrane permeability Catalysis Without a catalyst the reactions to digest starch would happen at very slow rates Enzyme specificity

Starch digestion in the small intestine Illustrates many processes that we have learned about Membrane permeability Catalysis Enzyme specificity Three enzymes in villi membranes break the 1,6 bonds and the 1,4 products; dextrinase, maltase, glucosidase Salivary amylase begins the digestion. Most starch digestion happens in the small intestine with enzyme secretions from the pancreas. 1,4 bonds broken by pancreatic amylase These small sections are now broken down into maltose and maltotriose Glucose

Starch digestion in the small intestine Illustrates many processes that we have learned about Membrane permeability Catalysis Glucose is absorbed via: co-transport with sodium ions into the interstitial fluid via facilitated diffusion through large membrane pores into capillaries. Enzyme specificity

6.1.4 Draw and label a diagram of the digestive system. mouth esophagus stomach liver gall bladder pancreas small intestine large intestine rectum anus http://sciencevideos.wordpress.com Draw the Core

How do these properties mimic the wall of the small intestine? Dialysis tubing made from cellulose has pores in it that allow water and small molecules and ions to pass through freely, but not large molecules. How do these properties mimic the wall of the small intestine? What types of membrane transport can be modelled using dialysis tubing and what parts can’t? 10 mL of 1% starch solution 1 mL of water 10 mL of 1% starch solution 1 mL of 1% amylase solution Bags made of dialysis tubing Bags made of dialysis tubing Water Water

Predict whether the bag will gain or lose mass during the experiment. Cola drinks contain a mixture of substances with different particle sizes. This cola contains glucose, phosphoric acid, and caramel (a complex carbohydrate added to produce a brown color). Predict which substances will diffuse out of the bag, with reasons for your prediction. Predict whether the bag will gain or lose mass during the experiment. Cola, left to go flat before being put in a tube Bags made of dialysis tubing Water