Have you paid your AP money? Show me receipt Turn in labs

1. Have you paid your AP money? Show me receipt • Turn in labs • This week—Molecular and Genetics (2 parts in review book) • Get ready for Chapter 40-41 reading quiz

2. Chapters 40-41 Reading Quiz • Describe the difference between negative and positive feedback. • If a mouse and a small lizard of the same mass were placed in experimental chamber under identical environmental conditions, which animal would consume oxygen at a higher rate. Explain. • List 3 enzymes involved in digestion. • What is the difference between mechanical and chemical digestion? • What are 2 advantages of a longer alimentary canal for processing plant material that is difficult to digest?

3. 1) In negative feedback, a change triggers control mechanisms that counteract further change in that direction. In positive feedback, a change triggers mechanisms that amplify the change. • 2) The mouse would consume oxygen at a higher rate because it is an endoderm and therefore basal metabolic rate is higher. • 3) Salivary amylase, pancreatic amylase, pepsin, trypsin, chymostrypsin, bile, gastric juice • 4) Mechanical digestion involves breaking down food via teeth, chemical digestion involves using enzymes • 5) The increased time for transit allows for more extensive processing, and the increased surface area to volume provides greater opportunity for absorption.

4. Song • http://www.songsforteaching.com/intellitunes/digestion.htm • http://www.scitunes.com/

6. Exit Quiz 2 a) What is the goal of digestion? b)Give the role of 3 digestive organs. c)Give the role of 3 digestive enzymes. • BONUS: How is glucose maintained in homeostasis? (use colored diagram)

7. Ch. 41 Animal Nutrition

8. 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

9. Food types/feeding mechanisms • Heterotrophs • Opportunistic • Herbivore: eat autotrophs • Carnivore: eat other animals • Omnivore: both • Feeding Adaptations • Suspension-feeders: sift food from water (baleen whale) • Substrate-feeders: live in or on their food (leaf miner) (earthworm: deposit-feeder) • Fluid-feeders: suck fluids from a host (mosquito) • Bulk-feeders: eat large pieces of food (most animals)

10. How do animals get their food? filter (suspension) feeding substrate feeding fluid feeding bulk feeding

11. Overview of food processing • Ingest • taking in food • Digest • mechanical digestion • breaking up food into smaller pieces • chemical digestion • breaking down food into molecules small enough to be absorbed into cells • enzymes (hydrolysis) • Absorb • absorb across cell membrane • diffusion • active transport • Eliminate • undigested extracellular material passes out of digestive system intracellulardigestion extracellulardigestion

12. Digestive systems Everybody’s got one!

13. Mammalian digestion, I • Peristalsis: rhythmic waves of contraction by smooth muscle • Sphincters: ring-like valves that regulate passage of material • Accessory glands: salivary glands; pancreas; liver; gall bladder~ secrete digestive juices

14. Finish Chapter 40-41 colored drawings and turn them in11:15 • Label enzymes on colored drawing, staple in notebook

15. Digestive Animation • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter26/animation__organs_of_digestion.html

16. Swallowing (& not choking) • Epiglottis • problem: breathe & swallow through same orifice • flap of cartilage • closes trachea(windpipe) when swallowing • food travels down esophagus • Esophagus • move food along to stomach by peristalsis

17. Ingestion • Mouth • mechanical digestion • teeth • breaking up food • chemical digestion • saliva • amylase • enzyme digests starch • mucin • slippery protein (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

18. Stomach • Functions • food storage • can stretch to fit ~2L food • disinfect food • HCl = pH 2 • kills bacteria • breaks apart cells • chemical digestion • pepsin • enzyme breaks down proteins • secreted aspepsinogen • activated by HCl But the stomach is made out of protein! What stops the stomach from digesting itself? mucus secreted by stomach cells protects stomach lining

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

20. Coevolution of parasite & host 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 • Helicobacter pylori • 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

21. 1982 | 2005 Revolutionizing healthcare "for their discovery of the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease" Helicobacter pylori J. Robin Warren Barry Marshall

22. Small intestine • Function • major organ of digestion & absorption • chemical digestion • digestive enzymes • absorption through lining • over 6 meters! • small intestine has huge surface area = 300m2 (~size of tenniscourt) • Structure • 3 sections • duodenum = most digestion • jejunum= absorption of nutrients & water • ileum= absorption of nutrients & water

23. Duodenum • 1st section of small intestines • acid food from stomach mixes with digestive juices from accessory glands: • pancreas • liver • gall bladder

24. Pancreas • Digestive enzymes • peptidases • trypsin • trypsinogen • chymotrypsin • chimotrypsinogen • carboxypeptidase • procarboxypeptidase • pancreatic amylase • Buffers • reduces acidity • alkaline solution rich in bicarbonate (HCO3-) • buffers acidity of material from stomach small intestines Explain how this is a molecular example of structure-function theme.

25. Liver • Digestive System Functions • produces bile • stored ingallbladderuntil needed • breaks up fats • act like detergents to breakup fats Circulatory System Connection bile contains colors from old red blood cells collected in liver = iron in RBC rusts & makes feces brown

26. liver produces bile - stored in gall bladder break up fats stomach kills germs break up food digest proteins store food mouth break up food moisten food digest starch kill germs pancreas produces enzymes to digest proteins & starch

27. Mammalian digestion, III • Small intestine •duodenum •bile • Intestinal digestion: a-carbohydrate b-protein c- nucleic acid d-fat

28. Absorption by Small Intestines • Absorption through villi & microvilli • finger-like projections • increase surface area for absorption Ooooh… Structure-Functiontheme!

29. 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

30. Large intestines (colon) • Function • re-absorb water • use ~9 liters of water every day in digestive juices • > 90% of water reabsorbed • not enough water absorbed back to body • diarrhea • too much water absorbed back to body • constipation

31. You’ve gotcompany! Flora of large intestines • Living in the large intestine is a richflora of harmless, helpful bacteria • Escherichiacoli (E. coli) • a favorite research organism • bacteria produce vitamins • vitamin K; biotin, folic acid & other B vitamins • generate gases • by-product of bacterial metabolism • methane, hydrogen sulfide

32. Rectum • Last section of colon (large intestines) • eliminate feces • undigested materials • extracellular waste • mainly cellulose from plants • roughage or fiber • salts • masses of bacteria appendix

33. large intestines absorb water 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 small intestines breakdown food - proteins - starch - fats absorb nutrients pancreas produces enzymes to digest proteins & carbs

34. Evolutionary adaptations • Adaptations of herbivore vs. carnivore • specialization in teeth • length of digestive system • number & size of stomachs

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

36. 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

37. Symbiotic organisms • How can cows digest cellulose efficiently? • symbiotic bacteria in stomachs help digest cellulose-rich meals • rabbit vs. cow adaptation: eat feces vs. chew cud ruminant caprohagy Ruminants additional mechanical digestion by chewing food multiple times after mixing it with enzymes

38. Evolutionary adaptations • Dentition: an animal’s assortment of teeth • Digestive system length • Symbiosis • Ruminants