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Copyright Notice! This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from for as long as that.

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Presentation on theme: "Copyright Notice! This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from for as long as that."— Presentation transcript:

1 Copyright Notice! This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from for as long as that website is available. Images lacking photo credits are mine and, as long as you are engaged in non-profit educational missions, you have my permission to use my images and slides in your teaching. However, please notice that some of the images in these slides have an associated URL photo credit to provide you with the location of their original source within internet cyberspace. Those images may have separate copyright protection. If you are seeking permission for use of those images, you need to consult the original sources for such permission; they are NOT mine to give you permission.

2 Biology: life study of What is Life? Cellular Structure: the unit of life, one or many Growth: cell enlargement, cell number Evolution: long term adaptation Behavior: short term response to stimuli Reproduction: avoid extinction at death Metabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energy Movement: intracellular, movement, locomotion Properties of Life

3 Obtaining Food Heterotrophs need to feed on other organisms, their by- products, or their dead bodies to survive

4 Heterotrophic Organisms Herbivores: feed directly upon producers Carnivores: feed directly upon herbivores or other carnivores Omnivores: feed upon both producers and consumers Parasites: feed upon living organisms causing disease Saprobes: feed upon by-products and/or dead bodies (aka detritivore) Food is required as fuel for respiration: Cytosolic Glycolysis: sugars to pyruvate Mitochondrial Matrix Krebs Cycle: pyruvate to CO 2 and NADH Mitochondrial Cristae ETS/Oxidative Phosphorylation: NADH and O 2 to H 2 O and ADP + P i to ATP

5 Here is an invertebrate animal collecting plant byproducts. Nectar is a good supply of carbohydrate…not much else Pollen is a better supply of protein, vitamins, and minerals ©1996 Norton Presentation Maker, W. W. Norton & Company

6 Prokaryotes intake small organics from the surrounding medium… by facilitated diffusion or active transport across cell membrane Digestive enzymes secreted into the medium convert macromolecules into subunits for uptake Thus digestion is extracellular

7 Here is a fungus body…these penetrate living or dead tissues… The rhizoids or haustoria digest the material or cells they penetrate and siphon off small molecules to support the fungal mycelium. Fungal digestion is basically EXTERNAL: Digestive enzymes are secreted into the food Subunits are absorbed by diffusion and active transport saprobeparasite ©1996 Norton Presentation Maker, W. W. Norton & Company

8 These fungi are more active in their feeding... They trap and strangle their nematode prey: Dactylella drechsleri B Arthrobotrys dactyloides sticky traps lasso What is the difference between these two images? ©1996 Norton Presentation Maker, W. W. Norton & Company

9 Two Paramecium and one Pelomyxa An example of internal digestion ©1996 Norton Presentation Maker, W. W. Norton & Company Paramecium Pelomyxa engulfing prey by phagocytosis entrapment in food vacuole for digestion

10 The feeding of Paramecium itself is also internal digestion: capture cilia movement oral groove (alveolus) cytopharynx (mouth) macronucleus micronucleus food vacuole endocytosis (phagocytosis) exocytosis (anal pore) contractile vacuole enzymatic digestion subunit absorption waste elimination

11 lysosome Golgi endoplasmic reticulum food vacuole digestive vacuole exo- cytosis subunits enzymes waste Intracellular food digestion: phago- cytosis 1.phagocytosis of food vacuole and lysosome formation 3.lysosome + food vacuole = digestive vacuole 4.enzymatic digestion of food 5.absorption of subunits 6.exocytosis of waste

12 Obtaining Food The origin of animals? Most primitive animal? Parazoa (no true tissues) –sponges Metazoa (true tissues) –other animals Is there an protozoan that acts and eats like an animal? Choanoflagellates Choanocytes sponge feeding cells very similar! flagellum (undulipodium) microvilli cell body

13 Porifera – primitive animal 1.Incurrent pores: ostia 2.Body wall: choanocytes for filter feeding 3.Excurrent pore: osculum (here huge) 4.Body wall has mineral spicules 5.High cellular mobility and totipotency Photo credit: Mike please provide original source of this image

14 Gastrovascular cavity digestion in Cnidarian polyp gland cell secretes digestive enzymes to disintegrate prey item into smaller particles digestive cell takes in smaller particles for intracellular digestion This is a combination of external and internal digestion There is also a unique prey capture process in cnidarians ©1996 Norton Presentation Maker, W. W. Norton & Company and anus! a blind pouch system

15 prey capture enzyme secretion for external digestion phagocytosis for internal digestion A closer look: Receptor Cell Ciliary Receptor Interstitial Cell Cnidocil (modified cilium) Cnidocyte Nematocyst Epidermis Mesoglea Gastrodermis Granular secretions Digestive Cell Circular Muscle Fibrils Longitudinal Muscle Fibrils Gland cell Cilia Food Vacuole Neuron

16 ©1996 Norton Presentation Maker, W. W. Norton & Company Cnidoblasts (cyan) contain nematocysts (yellow and blue) This feature of cnidarians is perhaps most famous in the scyphozoans (jellyfish) and hydrozoans (Portuguese-man-o-war)

17 ©1996 Norton Presentation Maker, W. W. Norton & Company In flatworms, such as Dugesia, and like cnidarians, the mouth is also the anus…the digestive system is a blind pouch. What do these corrugations do for Dugesia? Increase the surface area for nutrient absorption. ocellus also serves as the anus…a blind- pouch system

18 mouth radula valve plates gonad heart pericardial cavity (coelom) mantle anus foot digestive gland nephridium stomach ventral nerve cord (not shown) This cartoon shows a longitudinal slice of a chiton with the three principal parts: foot (locomotion or attachment), visceral mass (internal organs), and mantle (secretes the valves). The radula scrapes food from environmental surfaces. auricle ventricle nephridiopore gonopore hemocoel dorsal aorta …a tubular digestive system

19 As for most molluscs, chitons use a radula to scrape their food from environmental surfaces. Below is a radula removed from a chiton mouth. Bivalve molluscs are filter feeders, however.

20 Mollusc – Feeding Photos: Cleveland P. Hickman, Jr.

21 ©1996 Norton Presentation Maker, W. W. Norton & Company Earthworms also have a tubular digestive system

22 ©1996 Norton Presentation Maker, W. W. Norton & Company Earthworms also have a tubular digestive system intakemuscular grinding enzymatic digestion subunit uptake waste elimination

23 molting animals: shed their exoskeleton to grow What does this mean? Not a tetrachotomy! The parsimonious dichotomies are still unknown Ecdysozoa Phylogeny

24 Chitin Hard exoskeleton Fungi, Nematodes, Tardigrades Arthropods, insects and crustaceans Malpighian tubules Cyclomorphosis ß 1-4 glycosidic bond like cellulose, but includes a nitrogen atom. Difficult to digest. Chitinase/cellulase only produced in certain organisms. O CH 2 OH OH H NHNH O=C CH 3 H O H H O N-acetyl glucosamine O CH 2 OH OH H NHNH O=C CH 3 H H H O CH 2 OH OH H NHNH O=C CH 3 H O H H O LM or SEM?

25 Nematode Tubular Digestive System Stylet Esophagus Digestive glands Intestine Anus

26 Nematode Diseases of Humans Thread Worm Whipworm Pinworm Trichinosis Hookworm Filarial worms (elephantiasis, filariasis)

27 Spider Anatomy: Not that different from a mollusc in many ways… but are not in Phylum Mollusca…They are Phylum Arthropoda but not Class Insecta. Fang injects venom with digestive enzymes into prey The chelicera support tube as stomach sucks in liquified prey tissues Food passes through intestines for complete digestion/absorption Waste eliminated from anus Sub-Phylum: Chelicerata Class: Arachnida Spinnerets extrude silk fibers organized to capture prey to be food. octopod

28 Insecta: the largest class of Arthropods Out-numbers all other animals combined! Found in just about every environment…except marine! Entomology: the study of insects Evolved in Devonian period 400 MYBP smelling food seeing food hexapod

29 A look inside the digestive system: Mandibles chop food sideways Stomach holds food, grinds food Digestive gland injects enzymes Intestine absorbs subunits Rectum dehydrates wastes Anus ejects fecal pellet Stomach Rectum Digestive Gland Intestine (hindgut)

30 1.Brain: Sensing Food 2.Cardiac stomach 3.Pyloric stomach 4.Heart 5.Intestine 6.Digestive gland hepatopancreas 7.Anus anasoniclumixtz3/photography/lobster.jpg tures/JKPhotoGlry/Lobster-SideView.jpg decapod

31 Cycliophoran attached to lobster mouthparts. May be several species on a single animal. Discovery 1995! Photo credit: Mike please provide original source of this image…is this a maxilliped? jointed mouthparts for grasping, tearing food

32 ©1996 Norton Presentation Maker, W. W. Norton & Company This female mosquito has sensory organs to locate the victim animal (thermal, CO 2 ) and its blood vessels (octenol). She also has a stylet to pierce into an animals circulation system. piercing stylet She has a diverticulum to hold the blood meal for later use. She lives for 4-5 days on this one blood meal. The blood protein is used for laying a raft of eggs in water.

33 esophagus gizzard crop intestine stomach rectum cloaca Most birds have a crop for holding food to feed offspring. The gizzard assists in mechanical grinding of food. The intestine does: enzymatic digestion subunit uptake The rectum holds and partially dehydrates waste The cloaca is a single passage area for: digestive, urinary, and reproductive systems

34 ©1996 Norton Presentation Maker, W. W. Norton & Company Blue whales and other baleen whales are filter feeders You can see the baleen (teeth) of this whale that filter out krill

35 ©1996 Norton Presentation Maker, W. W. Norton & Company In most vertebrates, digestion begins with mastication using teeth Infection of the gums (periodontitis) is associated with endocarditis! In humans, tools (knives, blender, cooking pots) are used to initiate food preparation externally! Human Molar l.s. connective tissue bone

36 ©1996 Norton Presentation Maker, W. W. Norton & Company Dentition may include cutting, tearing, and grinding teeth Juvenile teeth may be replaced by adult teeth cutting tearing grinding Human dentition indicates we are omnivores!

37 ©1996 Norton Presentation Maker, W. W. Norton & Company snake beaver deer dog Among vertebrates the dentition has functional significance: grasping and angled back for swallowing prey whole muscular lips tear off leaves, molars grind them Huge indeterminate incisors slash into young tree trunks, molars grind plant material large canine teeth and pointed molars (more like canines), designed for tearing animal flesh…minimal grinding of tissue

38 ©1996 Norton Presentation Maker, W. W. Norton & Company The human digestive system: amylase Not shown: ventilation system connects at glottis in throat (pharynx) peristalsis

39 ©1996 Norton Presentation Maker, W. W. Norton & Company The movement of food in the digestive tube is by peristalsis

40 ©1996 Norton Presentation Maker, W. W. Norton & Company The human digestive system: amylase pepsin, HCl bile (emulsifier) trypsin, amylase, H 2 CO 3 (alk), lipase subunit absorption bacterial culture unknown water reabsorption waste holding, elimination acidic portion alkaline portion

41 ©1996 Norton Presentation Maker, W. W. Norton & Company An intestinal cross section reveals the increased surface area: circular muscles for peristalsis

42 ©1996 Norton Presentation Maker, W. W. Norton & Company To increase the surface area of the absorptive regions of the intestine, the lining is corrugated and lined with villi villi

43 ©1996 Norton Presentation Maker, W. W. Norton & Company The villi of the intestine have good blood supply for nutrient uptake Notice how the villus is coated with microvilli…for more area! sugars, amino acids, nucleotides

44 ©1996 Norton Presentation Maker, W. W. Norton & Company Here you can see the microvilli from a single villus villus microvilli

45 ©1996 Norton Presentation Maker, W. W. Norton & Company The adult (frog) has a shorter digestive system… …than the larva (tadpole) Can you speculate why this might have evolved? What evidence would you gather to test your hypothesis?

46 Horses cannot digest much of their food. Microbes are only in the caecum. Horse manure makes good compost and food for fungi. Equus caballus Why did the Franklin Mushroom Farm move to PA?

47 Because their microbes are in their caecum too, rabbits pass material through their digestive system twice. Recent meals pass as cecotropes, which the rabbit eats to re-digest the materials that the microbes liberate. As cecotropes pass through the second time, they are dehydrated as the familiar rabbit pellets. Oryctolagus cuniculus

48 ©1996 Norton Presentation Maker, W. W. Norton & Company Ruminant animals use bacteria and archaeons to assist digestion but early in the pathway… In ruminants, the microbe culture is mixed with masticated food in the rumen. The mixture is masticated repeatedly (chewing the cud) from this rumen to assist fermentation… especially hydrolysis of cellulose. Then the mixture passes to the rest of the digestive system. Bos taurus to rechew fermented cud fresh food bolus enters fresh food mixed with microbes including methanogens fermentation breaks down cellulose finish stomach digestion

49 ©1996 Norton Presentation Maker, W. W. Norton & Company The herbivorous tropical bird, the hoatzin, uses a muscular crop for its fermentation vat. It can represent 20% of the birds total weight! It is a poor flier. Its young falling, into swamps below, crawl back up into the nest using claws on the wings (like dinosaurs). Opisthocomus hoazin

50 Digestion of polysaccharides amylase Starch maltase Maltose Glucose These monosaccharides are ready for absorption from the digestive system. glu -1,4 glycosidic bond

51 terminal AA removers dipeptide splitter Individual Amino Acids For Absorption in Small Intestine Protein digestion in mammals: HisGluTyrThrLysHisGluSerArgAspTrpThrPhe amino end carboxyl end Stomach Pancreas pepsin HisGluTyrThrLysHisGluSerArgAspTrpThrPhe HisGluTyrThrLysHisGluSerArgAspTrpThrPhe HisGluTyrThrLysHisGluSerArgAspTrpThrPhe HisGluTyrThrLysHisGluSerArgAspTrpThrPhe trypsin chymotrypsin carboxypeptidaseaminopeptidase dipeptidase Proteins are polymers of some 22 different amino acids Enzymes cleave the peptide bond during… recognize phenolic AA, cleave amino side recognize phenolic AA, cleave carboxyl side recognize basic AA, cleave carboxyl side cleave AA from amino endcleave AA from carboxyl end recognize dipeptide, cleave peptide bond

52 ©1996 Norton Presentation Maker, W. W. Norton & Company Chymotrypsinogen conversion into chymotrypsin Chymotrypsinogen from pancreas is inactive Activation by acidic pepsin cleavage Finished chymotrypsin with active site recognizing Tyr, Trp and Phe How do you make digestive enzymes without digesting yourself?

53 Summary of macromolecule digestion into subunits Disaccharides maltose sucrose lactose Monosaccharides gluose frucose galactose Polysaccharides starch (amylose) salivary amylase pancreatic amylase intestinal maltase sucrase lactase Proteins Peptides Amino Acids Endopeptidases: stomach pepsin pancreatic trypsin pancreatic chymotrypsin Exopeptidases: pancreatic intestinal Fats (triglycerides) Emulsified fats liver bile monoglycerides fatty acids glycerol direct absorption pancreatic lipase

54 >75% Dutch, Swedes, Danes, Swiss, US Whites, Germans, Slavs, Northern French, Northern Italians, Tutsi, Fulani (milk traditionally in adult diet) <60% Indian, Southern Italians, Saami, US Hispanics, Balkans, Mexicans, Maasai, Southern French, Greeks, South Americans, African Americans, Lebanese <20% Central Asians, Eskimo, Australian Aborigines, Bantu, Chinese, Southeast Asians, Native Americans (no milk in traditional adult diet) Having mutation in adult shutdown of lactase production In normal human genotypes, adult lactase production is shut down. Fermentation of milk-based food only occurs by bacteria in the large intestine. This results in cramps, gas, and diarrhea! Lactose intolerance. lactoseglucose + galactose lactase

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