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Copyright Notice! This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from plantphys.info 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.
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Biology: What is Life? life study of Properties of Life
Cellular Structure: the unit of life, one or many Metabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energy Growth: cell enlargement, cell number Movement: intracellular, movement, locomotion Reproduction: avoid extinction at death Behavior: short term response to stimuli Evolution: long term adaptation
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Obtaining Food Heterotrophs need to
Obtaining Food Heterotrophs need to feed on other organisms, their by-products, or their dead bodies to survive
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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 CO2 and NADH Mitochondrial Cristae ETS/Oxidative Phosphorylation: NADH and O2 to H2O and ADP + Pi to ATP
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Here is an invertebrate animal collecting plant byproducts.
©1996 Norton Presentation Maker, W. W. Norton & Company Nectar is a good supply of carbohydrate…not much else Pollen is a better supply of protein, vitamins, and minerals
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Prokaryotes intake small organics from the surrounding medium…
by facilitated diffusion or active transport across cell membrane Thus digestion is extracellular Digestive enzymes secreted into the medium convert macromolecules into subunits for uptake
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Here is a fungus body…these penetrate living or dead tissues…
saprobe parasite ©1996 Norton Presentation Maker, W. W. Norton & Company 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
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These fungi are more “active” in their feeding...
They trap and strangle their nematode prey: Dactylella drechsleri B Arthrobotrys dactyloides sticky traps lasso ©1996 Norton Presentation Maker, W. W. Norton & Company What is the difference between these two images?
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engulfing prey by phagocytosis
Two Paramecium and one Pelomyxa engulfing prey by phagocytosis Paramecium ©1996 Norton Presentation Maker, W. W. Norton & Company entrapment in food vacuole for digestion Pelomyxa An example of internal digestion
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The feeding of Paramecium itself is also internal digestion:
cytopharynx (mouth) waste elimination oral groove (alveolus) endocytosis (phagocytosis) cilia movement exocytosis (anal pore) contractile vacuole capture food vacuole contractile vacuole subunit absorption enzymatic digestion micronucleus macronucleus
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Intracellular food digestion:
Golgi lysosome enzymes endoplasmic reticulum subunits waste exo- cytosis phago- cytosis food vacuole digestive vacuole phagocytosis of food food vacuole and lysosome formation lysosome + food vacuole = digestive vacuole enzymatic digestion of food absorption of subunits exocytosis of waste
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Obtaining Food The origin of animals?
flagellum (undulipodium) microvilli cell body 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!
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Porifera – primitive animal
Incurrent pores: ostia Body wall: choanocytes for filter feeding Excurrent pore: osculum (here huge) Body wall has mineral spicules High cellular mobility and totipotency Photo credit: Mike please provide original source of this image
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Gastrovascular cavity digestion in Cnidarian polyp
gland cell secretes digestive enzymes to disintegrate prey item into smaller particles and anus! ©1996 Norton Presentation Maker, W. W. Norton & Company a blind pouch system 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
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A closer look: prey capture phagocytosis for internal digestion
Cnidocil (modified cilium) Ciliary Receptor Cnidocyte prey capture Interstitial Cell Receptor Cell Nematocyst Epidermis Neuron Longitudinal Muscle Fibrils Mesoglea Circular Muscle Fibrils Gastrodermis Digestive Cell phagocytosis for internal digestion Granular secretions enzyme secretion for external digestion Food Vacuole Gland cell Cilia
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Cnidoblasts (cyan) contain nematocysts (yellow and blue)
©1996 Norton Presentation Maker, W. W. Norton & Company This feature of cnidarians is perhaps most famous in the scyphozoans (jellyfish) and hydrozoans (Portuguese-man-o-war)
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What do these corrugations do for Dugesia?
In flatworms, such as Dugesia, and like cnidarians, the mouth is also the anus…the digestive system is a blind pouch. ocellus What do these corrugations do for Dugesia? Increase the surface area for nutrient absorption. ©1996 Norton Presentation Maker, W. W. Norton & Company also serves as the anus…a blind-pouch system
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The radula scrapes food from environmental surfaces.
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. dorsal aorta gonad heart valve plates pericardial cavity (coelom) hemocoel ventricle radula auricle mantle mouth anus foot digestive gland stomach nephridium nephridiopore ventral nerve cord (not shown) gonopore …a tubular digestive system
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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.
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Mollusc – Feeding Photos: Cleveland P. Hickman, Jr.
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Earthworms also have a tubular digestive system
©1996 Norton Presentation Maker, W. W. Norton & Company
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Earthworms also have a tubular digestive system
waste elimination subunit uptake ©1996 Norton Presentation Maker, W. W. Norton & Company enzymatic digestion intake muscular grinding
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molting animals: shed their exoskeleton to grow
Ecdysozoa Phylogeny molting animals: shed their exoskeleton to grow Not a tetrachotomy! The parsimonious dichotomies are still unknown What does this mean?
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Chitin LM or SEM? Hard exoskeleton Fungi, Nematodes, Tardigrades
Arthropods, insects and crustaceans Malpighian tubules Cyclomorphosis LM or SEM? O CH2OH OH H NH O=C CH3 ß 1-4 glycosidic bond like cellulose, but includes a nitrogen atom. Difficult to digest. Chitinase/cellulase only produced in certain organisms. N-acetyl glucosamine O CH2OH OH H NH O=C CH3
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Nematode Tubular Digestive System
Nematode Tubular Digestive System Stylet Esophagus Digestive glands Anus Intestine
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Nematode Diseases of Humans
Thread Worm Whipworm Pinworm Trichinosis Hookworm Filarial worms (elephantiasis, filariasis)
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Spinnerets extrude silk fibers organized to capture prey to be food.
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 Spinnerets extrude silk fibers organized to capture prey to be food. octopod Sub-Phylum: Chelicerata Class: Arachnida
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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
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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 Digestive Gland Rectum Stomach Intestine (hindgut)
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Digestive gland hepatopancreas Anus
Brain: Sensing Food Cardiac stomach Pyloric stomach Heart Intestine Digestive gland hepatopancreas Anus decapod
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jointed mouthparts for grasping, tearing food
Photo credit: Mike please provide original source of this image…is this a maxilliped? Cycliophoran attached to lobster mouthparts. May be several species on a single animal. Discovery 1995!
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She has a diverticulum to hold the blood meal for later use.
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. This female mosquito has sensory organs to locate the victim animal (thermal, CO2) and it’s blood vessels (octenol). She also has a stylet to pierce into an animal’s circulation system. ©1996 Norton Presentation Maker, W. W. Norton & Company piercing stylet
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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 esophagus intestine stomach gizzard crop rectum cloaca The rectum holds and partially dehydrates waste The cloaca is a single passage area for: digestive, urinary, and reproductive systems
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Blue whales and other baleen whales are filter feeders
You can see the baleen (teeth) of this whale that filter out krill ©1996 Norton Presentation Maker, W. W. Norton & Company
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In most vertebrates, digestion begins with mastication using teeth
Human Molar l.s. connective tissue bone ©1996 Norton Presentation Maker, W. W. Norton & Company Infection of the gums (periodontitis) is associated with endocarditis! In humans, tools (knives, blender, cooking pots) are used to initiate food preparation externally!
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Human dentition indicates we are omnivores!
Dentition may include cutting, tearing, and grinding teeth cutting tearing grinding ©1996 Norton Presentation Maker, W. W. Norton & Company Juvenile teeth may be replaced by adult teeth Human dentition indicates we are omnivores!
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Among vertebrates the dentition has functional significance:
grasping and angled back for swallowing prey whole snake deer muscular lips tear off leaves, molars grind them beaver ©1996 Norton Presentation Maker, W. W. Norton & Company Huge indeterminate incisors slash into young tree trunks, molars grind plant material dog large canine teeth and pointed molars (more like canines), designed for tearing animal flesh…minimal grinding of tissue
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The human digestive system:
Not shown: ventilation system connects at glottis in throat (pharynx) amylase peristalsis ©1996 Norton Presentation Maker, W. W. Norton & Company
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The movement of food in the digestive tube is by peristalsis
©1996 Norton Presentation Maker, W. W. Norton & Company
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The human digestive system:
amylase acidic portion ©1996 Norton Presentation Maker, W. W. Norton & Company pepsin, HCl trypsin, amylase, H2CO3 (alk), lipase bile (emulsifier) alkaline portion water reabsorption bacterial culture subunit absorption waste holding, elimination unknown 40
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circular muscles for peristalsis
An intestinal cross section reveals the increased surface area: circular muscles for peristalsis ©1996 Norton Presentation Maker, W. W. Norton & Company
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To increase the surface area of the absorptive regions of the intestine, the lining is corrugated and lined with villi villi ©1996 Norton Presentation Maker, W. W. Norton & Company
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The villi of the intestine have good blood supply for nutrient uptake
sugars, amino acids, nucleotides ©1996 Norton Presentation Maker, W. W. Norton & Company Notice how the villus is coated with microvilli…for more area!
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microvilli villus Here you can see the microvilli from a single villus
©1996 Norton Presentation Maker, W. W. Norton & Company villus
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The adult (frog) has a shorter digestive system…
…than the larva (tadpole) ©1996 Norton Presentation Maker, W. W. Norton & Company Can you speculate why this might have evolved? What evidence would you gather to test your hypothesis?
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Why did the Franklin Mushroom Farm move to PA? Equus caballus
Horses cannot digest much of their food. Microbes are only in the caecum. Horse manure makes good compost and food for fungi. Why did the Franklin Mushroom Farm move to PA? Equus caballus
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Oryctolagus cuniculus
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
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Then the mixture passes to the rest of the digestive system.
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 ©1996 Norton Presentation Maker, W. W. Norton & Company fresh food bolus enters to rechew fermented cud fresh food mixed with microbes including methanogens finish stomach digestion fermentation breaks down cellulose
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It can represent 20% of the bird’s total weight!
The herbivorous tropical bird, the hoatzin, uses a muscular crop for its fermentation vat. It can represent 20% of the bird’s 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). ©1996 Norton Presentation Maker, W. W. Norton & Company Opisthocomus hoazin
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Digestion of polysaccharides -1,4 glycosidic bond
Starch amylase amylase amylase glu Maltose Glucose maltase maltase Glucose These monosaccharides are ready for absorption from the digestive system.
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Protein digestion in mammals:
Proteins are polymers of some 22 different amino acids Enzymes cleave the peptide bond during… Protein digestion in mammals: Stomach pepsin recognize phenolic AA, cleave amino side amino end His Glu Tyr Thr Lys His Glu Ser Arg Asp Trp Thr Phe carboxyl end recognize phenolic AA, cleave carboxyl side Pancreas chymotrypsin trypsin recognize basic AA, cleave carboxyl side His Glu Tyr Thr Lys Ser Arg Asp Trp Phe cleave AA from amino end cleave AA from carboxyl end terminal AA removers aminopeptidase carboxypeptidase His Glu Tyr Thr Lys Ser Arg Asp Trp Phe dipeptide splitter recognize dipeptide, cleave peptide bond dipeptidase His Glu Tyr Thr Lys Ser Arg Asp Trp Phe His Glu Tyr Thr Lys Ser Arg Asp Trp Phe Individual Amino Acids For Absorption in Small Intestine
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Chymotrypsinogen conversion into chymotrypsin
How do you make digestive enzymes without digesting yourself? Chymotrypsinogen conversion into chymotrypsin Chymotrypsinogen from pancreas is inactive ©1996 Norton Presentation Maker, W. W. Norton & Company Finished chymotrypsin with active site recognizing Tyr, Trp and Phe Activation by acidic pepsin cleavage
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pancreatic chymotrypsin
Summary of macromolecule digestion into subunits Polysaccharides starch (amylose) Disaccharides maltose sucrose lactose Monosaccharides gluose frucose galactose salivary amylase pancreatic amylase intestinal maltase sucrase lactase Proteins Peptides Amino Acids Endopeptidases: stomach pepsin pancreatic trypsin pancreatic chymotrypsin Exopeptidases: pancreatic intestinal monoglycerides pancreatic lipase Emulsified fats Fats (triglycerides) fatty acids liver bile glycerol direct absorption
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Having mutation in adult shutdown of lactase production
lactose glucose + galactose 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. Having mutation in adult shutdown of lactase production >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)
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