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Ch 48 Digestion and Excretion. Ch 47 Sr’s and GR Q’s QUESTIONS? Innate/Adaptive Act out Ch 48 Intro HW CH 48 GRQ’s. Group Section 2 Overview of Digestion. Mouth/Esophagus Stomach Liver, Gall Bladder, Pancreas Small and Large Intestine Groups of 4
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Ch 48 Digestion and Excretion • Ch 47 Sr’sand GRQ’s QUESTIONS? • Innate/Adaptive Act out • Ch 48 Intro • HW CH 48 GRQ’s
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)
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
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
Carbohydrates: Structure • Contain: C, H, O • Monomers / Building Blocks: sugars (monosaccharides)
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
Sugar (sucrose) Carbohydrates: Examples
Starch Carbohydrates: Examples
Cellulose Carbohydrates: Examples
Lipids: Structure • Contain: C, H, O • Monomers: Triglycerides (3 fatty acids bonded to 1 glycerol)
Lipids: Role • Energy Storage • Insulation / Waterproofing • Biochemical Signals Found in: • Oils, Butter, Shortening • Dairy Products • Meat • Some veggies (like avocado) • Junk Food
Oils Waxes Steroids Hormones Lipids: Examples cholesterol testosterone
Proteins: Structure • Contain: C, N, O, H (S in some proteins) • Monomers: Amino Acids (22 different ones) • Shape is determined by amino acid sequence
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
Protein: Examples • Enzymes such as lactase
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!!
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
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
8. Ch 48 Digestion and Excretion • Group presentations Stomach – Large Intest. • Kidney and Nephron Function • Ch 48 GRQ QUESTIONS??? • HW Ch 48 SR’s
Ingestion - MOUTH • mechanical digestion • Teeth (incisors/molars) • breaking up food • chemical digestion • saliva • amylase • enzyme digests starch • Food chew moistened/chewed into a “bolus”
mouth break up food moisten food digest starch kill germs
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
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
stomach kills germs store food break up food digest proteins mouth break up food moisten food digest starch kill germs cardiacsphincter pyloricsphincter
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
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
Duodenum • 1st section of small intestines • acid food from stomach mixes with digestive juices from accessory glands: • pancreas • liver • gall bladder
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.
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
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
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
Absorption by Small Intestines • Absorption through villi & microvilli • finger-like projections • increase surface area for absorption
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!
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
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
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
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
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
Appendix Vestigial organ
Hungry for Information? Ask Questions!
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
Mammalian Kidney inferiorvena cava aorta adrenal gland kidney nephron ureter renal vein& artery epithelialcells bladder urethra
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”
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
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
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
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
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