12/9 Digestion after the stomachPresentation Transcript
Do Now Where would the digestion of fruit start? Where would the digestion of starch start? Which nutrients do you think could be absorbed without being digested in the gastrointestinal tract?
Do Now Fruit is a complex carbohydrate Digestion of sugars start in the mouth Starch is a complex carbohydrate Digestion of sugars start in the mouth Vitamins, Minerals, and Water No building blocks, right?
Aim: What happens to food after it moves out of the stomach?
A trip through the Gastrointestinal Tract… We enter through the mouth Become a bolus as we move through the esophagus Become chyme when we enter the stomach
After the stomach… CHYME enters the small intestines
Small Intestines Digestion is finished here; no digestion after Much of digestion takes place in first parts of the S.I. Absorption of nutrients occurs here! The surface of small intestines are covered with VILLI The surfaces of the villi are covered by MICROVILLI
Small Intestines Villi and Microvilli (villus and microvillus) Make the small intestine have HUGE SURFACE AREA…why? So the most possible absorption of nutrients can take place! Microvilli are like small fingers on finger! Huge surface area!
Which set of paper towels can absorb more?
After the small intestine… We enter the large intestine (colon) After the SI, much of the nutrients have been absorbed out of the chyme already All that’s left: water, cellulose, undigested material
Large Intestine (Colon) Main function of the colon: Absorbing Water If water cannot be absorbed – Diarrhea Think: if you don’t absorb the water, where does it go? To help food move better – Roughage Complex carbs, fiber, vegetables good sources of roughage
Enzymes in the Gastrointestinal System Mouth – salivary amylase Breaks down starches into smaller sugars Where carbohydrate digestion starts Stomach – pepsin Breaks down polypeptides into amino acids Where protein digestion starts
Enzymes in the Digestive System Small intestine gets enzymes from two places: 1. the pancreas releases enzymes 2. the small intestine lining secretes enzymes
Enzymes in the Digestive System Small intestine from pancreas Amylase – continues breakdown of carbohydrate, starch Trypsin – continues breakdown of protein Lipase – STARTS break down of fat NOTICE: lipase (lipid); fat digestion starts in the small intestine Small intestine from lining secretions Maltase, sucrase, lactase – breaks down carbs to sugars Peptidase – breaks down peptides into amino acids
Split into groups, work on packet
Citations All pictures taken from PowerPoint clipart and Google Pictures