1. THE HUMAN DIGESTIVE SYSTEM THE CHEMICAL DIGESTION

2. DIGESTION OF CARBOHYDRATES 1. Digestion of carbohydrates in mouth Cooked starch + water maltose+dextrin Salivary amylase Amylase Starch + water maltose+dextrin 2. Digestion of carbohydrates in duodenum

3. Digestion of carbohydrates inthe rest of the small intestine Maltose + water glucose+ glucose Maltase Sucrose Lactase Lactose + water glucose+ galactose Sucrose + water glucose+ fructose

4. Digestion of carbohydrates starts in mouth and continues in the duodenum Touching the chyme to the inner surface of duodenum Duodenum secretes secretin Given into the blood Stimulates the pancreas Pancreas produces pancreatic juice

5. DIGESTION OF PROTEIN Protein + water polypeptide (peptide) Pepsinogen + HCl pepsin (inactive) (active) 1. Protein digestion in stomach Milk casein +water Casein polypeptide +amino acids renine pepsin

6. Food in stomach Secretes gastrin hormone Given into blood Stimulates stomach glands To secrete HCl Pepsinogen, mucus and renin in baby’s Activate the pepsinogen to convert into pepsin

7. 2. Protein digestion in duodenum Trypsinogen +enterokinase trypsin (inactive) (active) Polypeptide + water peptide+ amino acids trypsin 3. Protein digestion in rest of the small intestine Peptide + water amino acids erepsin

8. DIGESTION OF LIPIDS Fat + bile fat droplets Fat droplets + water fatty acids + glycerol lipase

9. Chyme in the intestine Secretes cholecystokinin Stimulates liver to secrete bile Secreted into duodenum