Ch 48 Digestion and Excretion

1. Ch 48 Digestion and Excretion • Ch 47 Sr’sand GRQ’s QUESTIONS? • Innate/Adaptive Act out • Ch 48 Intro • HW CH 48 GRQ’s

2. Group Section 2 Overview of Digestion • Mouth/Esophagus • Stomach • Liver, Gall Bladder, Pancreas • Small and Large Intestine • Groups of 4 • Parts/Structure-function relationships/what digestion occurs. • Doc you can upload (and email to each other)

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. 48.1 6 classes of nutrients • C,L,P, Water, Minerals, & Vitamins • USDA food plate. • Calorie = unit of energy = amount of heat need to raise the temp of 1 gram of water by 1deg C

5. Carbohydrates: Structure • Contain: C, H, O • Monomers / Building Blocks: sugars (monosaccharides)

6. Carbohydrates: Role • The main energy source for living things • Structural components of cells (cell wall, etc) Found in: • Grains (bread, cereal, flour) • Fruits • Veggies • Sugars

7. Sugar (sucrose) Carbohydrates: Examples

8. Starch Carbohydrates: Examples

9. Cellulose Carbohydrates: Examples

10. Lipids: Structure • Contain: C, H, O • Monomers: Triglycerides (3 fatty acids bonded to 1 glycerol)

11. Lipids: Role • Energy Storage • Insulation / Waterproofing • Biochemical Signals Found in: • Oils, Butter, Shortening • Dairy Products • Meat • Some veggies (like avocado) • Junk Food

12. Oils Waxes Steroids Hormones Lipids: Examples cholesterol testosterone

13. Proteins: Structure • Contain: C, N, O, H (S in some proteins) • Monomers: Amino Acids (22 different ones) • Shape is determined by amino acid sequence

14. Proteins: Role • Enzymes (help reactions take place) • Carry out body functions • Structural Components (make up muscle, internal cell structure) Found in: • Meat • Dairy • Eggs • Nuts and Legumes

15. Protein: Examples • Enzymes such as lactase

16. Vitamins • Mostly cannot be synthesized by the body • Organic co-enzymes = help enzymes to function • Water or fat soluble. • Vitamins A,B,C, X, Y, Z etc!!

17. Minerals • Inorganic • Often co-factors needed to proper protein/enzyme function • Iron, Na, Ca, K, Iodine, P WATER Most of your body, reactions, excreting waste, thermoregulation etc

18. Section 2 Digestive system

19. Getting & Using Food • 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

20. 8. Ch 48 Digestion and Excretion • Group presentations Stomach – Large Intest. • Kidney and Nephron Function • Ch 48 GRQ QUESTIONS??? • HW Ch 48 SR’s

21. Human digestive systemAlimentary Canal

22. Ingestion - MOUTH • mechanical digestion • Teeth (incisors/molars) • breaking up food • chemical digestion • saliva • amylase • enzyme digests starch • Food chew moistened/chewed into a “bolus”

23. mouth break up food moisten food digest starch kill germs

24. Esophagus • Epiglottis • problem: breathe & swallow through same orifice • flap of cartilage • closes trachea (windpipe) when swallowing • food travels down esophagus • Esophagusbegins with pharnyx • move food along to stomach by peristalsis

25. 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 as pepsinogen • 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

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

27. Ulcers Coevolution of parasite & host 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

28. 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

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

30. What stopspancreasfrom digesting itself Pancreas Ooooooh! Zymogen! • 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.

31. pancreas produces enzymes to digest proteins & starch mouth break up food moisten food digest starch kill germs stomach kills germs break up food digest proteins store food

32. 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

33. 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

34. Absorption by Small Intestines • Absorption through villi & microvilli • finger-like projections • increase surface area for absorption

35. Absorption of Nutrients • Passive transport • fructose • Active (protein pumps) transport • pump amino acids, vitamins & glucose • against concentration gradients across intestinal cell membranes • allows intestine to absorb much higher proportion of nutrients in the intestine than would be possible with passive diffusion • worth the cost of ATP! nutrients are valuable…grab all you can get!

36. 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

37. 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

38. 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

39. 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

40. 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

41. Appendix Vestigial organ

42. Hungry for Information? Ask Questions!

43. Urinary System blood filtrate • Filter solutes out of blood & reabsorb H2O + desirable solutes • Key functions • filtration • fluids (water & solutes) filtered outof blood • reabsorption • selectively reabsorb (diffusion) needed water + solutes back to blood • secretion • pump out any other unwanted solutes to urine • excretion • expel concentrated urine (N waste + solutes + toxins) from body concentratedurine

44. Mammalian Kidney inferiorvena cava aorta adrenal gland kidney nephron ureter renal vein& artery epithelialcells bladder urethra

45. Nephron • Functional units of kidney • 1 million nephronsper kidney • Function • filter out urea & other solutes (salt, sugar…) • blood plasma filteredinto nephron • high pressure flow • selective reabsorption ofvaluable solutes & H2O back into bloodstream • greater flexibility & control whyselective reabsorption& not selectivefiltration? “counter current exchange system”

46. Mammalian kidney How candifferent sectionsallow the diffusionof different molecules? • Interaction of circulatory & excretory systems • Circulatory system • glomerulus = ball of capillaries • Excretory system • nephron • Bowman’s capsule • loop of Henle • proximal tubule • descending limb • ascending limb • distal tubule • collecting duct Proximal tubule Distal tubule Bowman’s capsule Glomerulus Glucose H2O Na+ Cl- Amino acids H2O H2O Na+ Cl- H2O Mg++ Ca++ H2O H2O Collecting duct Loop of Henle

47. Nephron: Filtration • At glomerulus • filtered out of blood • H2O • glucose • salts / ions • urea • not filtered out • cells • proteins high blood pressure in kidneysforce to push (filter) H2O & solutes out of blood vessel BIG problems when you start out with high blood pressure in systemhypertension = kidney damage

48. Descendinglimb Ascendinglimb Nephron: Re-absorption • Proximal tubule • reabsorbed back into blood • NaCl • active transport of Na+ • Cl– follows by diffusion • H2O • glucose • HCO3- • bicarbonate • buffer for blood pH

49. Descendinglimb Ascendinglimb Nephron: Re-absorption structure fitsfunction! • Loop of Henle • descending limb • high permeability to H2O • many aquaporins in cell membranes • low permeability to salt • few Na+ or Cl– channels • reabsorbed • H2O

50. Descendinglimb Ascendinglimb Nephron: Re-absorption structure fitsfunction! • Loop of Henle • ascending limb • low permeability to H2O • Cl- pump • Na+ follows by diffusion • different membrane proteins • reabsorbed • salts • maintains osmotic gradient