Animal Nutrition Human Digestion

1. Animal Nutrition Human Digestion

2. food O2 ATP What do animals need to live? • Animals make __________ using: • __________________ • __________________ • Animals _______________using: • __________________ • amino acids, sugars, fats, nucleotides • __________________ __________________

3. Different diets; different lives • All animals eat other organisms • ______________ • eat mainly _________ • gorillas, cows, rabbits, snails • ______________ • eat other __________ • sharks, hawks, spiders, snakes • ______________ • eat ___________________ • cockroaches, bears, raccoons, humans • humans evolved as hunters, scavengers & gatherers

4. Getting & Using Food • ________________ • taking in food • ________________ • __________________________ • breaking up food into smaller pieces • __________________________ • breaking down food into molecules small enough to be absorbed into cells • enzymes • ________________ • absorb across cell membrane • ___________________ • ___________________ • ________________ • undigested material passes out of body intracellulardigestion extracellulardigestion

5. Digestive systems Everybody’s got one!

6. Mouth • Functions • _______________________ • _______________ • break up food • _______________________ • __________________________ • ____________________________ • mucus • protects soft lining of digestive system • lubricates food for easier swallowing • buffers • neutralizes acid to prevent tooth decay • anti-bacterial chemicals • kill bacteria that enter mouth with food All thatin spit!

7. Swallowing (& not choking) • ________________________ • flap of cartilage • closes __________ (windpipe) when swallowing • food travels down _______________ • ________________________ • involuntary muscle contractions to move food along

8. Stomach • Functions • ______________________ • hydrochloric acid = pH 2 • kills bacteria • ______________________ • can stretch to fit ~2L food • ______________________ • _____________________ What stops the stomach from digesting itself? mucus secreted by stomach cells protects stomach lining

9. Ulcers Free of H. pylori Colonized by H. pylori • Used to think ulcers were caused by stress • tried to control with antacids • Now know ulcers caused by bacterial infection of stomach • H. pylori bacteria • now cure with antibiotics inflammation of stomach inflammation of esophagus H. pylori cell damaging proteins (VacA) inflammatory proteins (CagA)   cytokines helper T cells neutrophil cells white blood cells

10. Small intestine • Functions • ______________________ • _______________________ • amylase from pancreas • _______________________ • trypsin & chymotrypsin from pancreas • _______________________ • bile from liver & lipase from pancreas • ______________________ • nutrients move into body cells by: • diffusion • active transport This iswhere all thework is done!

11. Absorption by Small Intestines • ________________________________ • finger-like projections • _________________________________ SMALL INTESTINES6 meters long,but can stretchto cover a tennis court

12. Pancreas • _______________________________ • __________________________ • trypsin, chymotrypsin • __________________________ • amylase • __________________________ • lipase • Buffers • neutralizes acid from stomach smallintestine pancreas

13. Liver & Gall Bladder • ________________________ • _________________________________ • _________________________________ • that’s why you can have your gall bladder removed bile contains colors from old red blood cells collected in liver = iron in RBC rusts & makes feces brown

14. Large intestines (colon) • Function • ___________________________________ • use ~9 liters of water every day in digestive juices • if don’t reabsorb water, would die of dehydration • > 90% of water re-absorbed • not enough water re-absorbed • ____________________ • can be fatal! • too much water re-absorbed • ____________________ • reabsorb by diffusion

15. You’ve got company! • Living in the large intestine is a community of helpful bacteria • Escherichia coli:___________ • ____________________________ • digests fruits & vegetables • ____________________________ • vitamin K & B vitamins • ____________________________ • by-product of bacterial metabolism • methane, hydrogen sulfide • STINKY! PEE-YOO!

16. Rectum • Last section of large intestines • eliminate feces • what’s left over? • ___________________________ • mainly cellulose from plants • called ___________________________ • keeps everything moving & cleans out intestines • masses of bacteria So don’t forget to wash your hands!

17. Different diets; different bodies • Adaptations of herbivore vs. carnivore • teeth • length of digestive system • number & size of stomachs

18. Teeth • _______________ • sharp ripping teeth • “canines” • _______________ • wide grinding teeth • molars • _______________ • both kinds of teeth

19. Length of digestive system • Herbivores & omnivores • long digestive systems • harder to digest cellulose (cell walls) • bacteria in intestines help • Carnivores • short digestive systems appendix

20. Eating a balanced diet • What happens if an animal’s diet is missing an essential nutrient? • deficiency diseases • scurvy — vitamin C (collagen production) • rickets — vitamin D (calcium absorption) • blindness — vitamin A (retinol production) • anemia — vitamin B12 (coenzyme function) • kwashiorkor — protein

21. Vegetarian diets • Need to make sure you get enough protein • 20 amino acids to make protein • 12 humans can make • 8 we have to eat = “essential amino acids” • Grains (like corn) have 6 amino acids • missing 2 • Beans (like soybean & red beans) have 6 amino acids • missing different 2 • mix beans & grainsfor complete group of amino acids • rice & beans • taco/tortilla & beans • tofu & rice • peanut butter & bread

22. ______________ high liver low ______________ liver Homeostasis Blood Sugar insulin body cells takeup sugar _________ liver stores_________ reduces________ blood sugar level liver releases_________ triggers_________ Feedback ucagon