Ch 39 Nutrition, Digestion and absoption

1. Ch 39 Nutrition, Digestion and absoption AP lecture

2. Recap • Heterotrophic • Autotrophic • Catabolism • Glycogen

3. food O2 ATP What do animals need to live? • Animals make energyusing: • food • oxygen • Animals build bodiesusing: • food for raw materials • amino acids, sugars, fats, nucleotides • ATP energy for synthesis

4. Teeth • Carnivore • sharp ripping teeth • “canines” • Herbivore • wide grinding teeth • molars • Omnivore • both kinds of teeth

5. Essential nutrients • Can not be synthesized in the body but are absolutely required • Macronutrients • Required in large amounts • Micronutrients • Required in small amounts *amino acids*

6. Essential minerals • Chemical element required in the diet • Calcium (macronutrient), Iron (micronutrient), and potassium

7. Essential Vitamins • Carbon compounds • Water soluble • Eliminated in the urine • Fat soluble • Build up in the body fat and become toxic to the liver • Vitamin D • Helps absorb calcium

8. Nutrient Deficiencies • Malnutrition • Lack of essential nutrients in the diet Can lead to diseases and organ failure

9. Digestive System • Function: break down large molecules into smaller, absorbable molecules *monomers and hydrolysis* • Tubular gut, two openings- one at each end

10. Digestive systems Everybody’s got one!

11. Length of digestive system • Carnivores • short digestive system • protein easier to digest than cellulose • Herbivores & omnivores • long digestive system • more time to digest cellulose • symbiotic bacteria in gut

12. Overview of food flow • Mouth • Pharynx • Esophagus • Stomach • Small intestine • Large intestine • Rectum

14. Mouth • Digestion starts • Chewing and amylase- starch digesting enzyme • Bolus- ball of food • Swallowing is an autonomic reflex • Sphincter at the base of the esophagus • Epiglottis covers the trachea to make sure food does not pass into the windpipe

16. Stomach • Holds and breaks up food • Starts protein digestion • Pepsinogen is inactive so it will not harm the stomach tissue lining • Pepsin is activated by HCl secreted by the stomach • Helps with digestion

17. Stomach pH is around 1 • Can cause ulcers • Chyme- partly digested food, acid and enzymes • Smooth muscle pushed chyme into the small intestines through a pyloric sphincter

18. stomach kills germs store food break up food digest proteins mouth break up food moisten food digest starch kill germs cardiacsphincter pyloricsphincter

19. Small intestine • Digestion of carbohydrates and proteins continues • Digestion of fat • Absorbs nutrients • Duodenum – most digestion • Jejunum- absorb • Ileum – absorb

20. * Accessory organs* Liver – makes and secretes bile which is then stored in the gall bladder (then to duodenum) blood from the stomach goes to the liver to be filtered of toxins and to build macromolecules Pancreas – endocrine and exocrine gland digestive juices, glucagon and insulin

21. small intestines breakdown all foods - proteins - starch - fats - nucleic acids absorb nutrients stomach kills germs break up food digest proteins store food mouth break up food moisten food digest starch kill germs liver produces bile - stored in gall bladder break up fats pancreas produces enzymes to digest proteins & starch

22. Large intestine (a.k.a) colon • Absorbs water and builds feces *dehydration from diarrhea*