*Chapter 5: Eukaryotic MicrobesWeek 4Professor Autieri

Early nucleusEarly endoplasmic reticulumNuclear envelopeEarly mitochondriaAncestral cellMany protozoa, animalsAlgae, higher plantsChloroplastCell wallSmaller bacterium becomes a permanent resident of its Host s cytoplasm; it multiplies and is passed on during cell division. It utilizes aerobic metabolism and increases energy availability for the host.The larger cell engulfs the smaller one; smaller one survives and remains surrounded by the vacuolarmembrane.Ancestral eukaryotic cell develops additional membrane pouches that become the endoplasmic reticulum and Golgi apparatus. Photosynthetic bacteria (similar to cyanobacteria) are also engulfed; they develop into chloroplasts.A smaller prokaryotic cell similar to purple bacteria that can use oxygenCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.A larger prokaryotic cell such as an archaea has a flexible outer envelope and Mesosomelike internal membranes to enclose the nucleoid. The History of EukaryotesThey first appeared approximately 2 billion years ago

Evidence suggests evolution from prokaryotic organisms by symbiosis

Organelles originated from prokaryotic cells trapped inside them

* Image by D. J. Patterson (provided by micro*scope http://microscope.mbl.edu)

Ancient Eukaryotes*ChloroplastsCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Andrew KnollCell wally. Andrew Knoll(a)(b)

*Eukaryotic Microbes

*The Eukaryotic CellNuclear membrane with poresNucleolusNucleusCentrioles*Microvilli/ GlycocalyxRough endoplasmic reticulum with ribosomes MitochondrionCell wall*Cell membraneGolgi apparatusMicrotubulesChloroplast**Structure not present in all cell typesSmooth endoplasmic reticulumLysosomeMicrofilamentsFlagellum*Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

External StructuresLocomotor appendages: Flagella Long, sheathed cylinder containing microtubules Covered by an extension of the cell membrane 10X thicker than prokaryotic flagellaFunction in motility*shortglycocalyxfringeciliarymembrane singletB subfiberof doubletouterdyneinarm(a)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.y.Courtesy Richard AllenCellMembraneCourtesy Richard AllenMicrotubulesCiliumbb(b)(c) Whips back and forth and pushes in snakelike patternTwiddles the tipLashes, grabs the substrate, and pulls

MicronucleusOral groove with gulletMacronucleusContractile vacuoleCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.*External StructuresLocomotor appendages: Cilia Found only on a single group of protozoa and certain animal cellsFunction in motility, feeding, and filtering (a)Power strokeRecovery stroke(b)

External StructuresGlycocalyxAn outermost boundary that comes into direct contact with environmentUsually composed of polysaccharidesA slime layer or a capsuleFunctions in adherence, protection, and signal receptionBeneath the glycocalyx Fungi and most algae have a thick, rigid cell wallProtozoa, a few algae, and all animal cells lack a cell wall and have only a membrane

*

Boundary of the CellCell wallRigid, provides structural support and shapeFungi have thick inner layer of polysaccharide fibers composed of chitin Algae substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate

*

Internal StructuresNucleusCompact sphere, most prominent organelle of eukaryotic cellNuclear envelope composed of two parallel membranes separated by a narrow space and is perforated with poresContains chromosomesNucleolus dark area for rRNA synthesis and ribosome assembly*Nuclear envelopeEndoplasmic reticulumNuclear poreNucleolusChromatin(a) Don Fawcett/Visuals UnlimitedNuclear poreNucleolusNuclear envelope(b)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Nuclear changes during Mitosis*Cleavage furrowChromatinNucleolusNuclear envelopeCell membraneCytoplasmDaughter cellsInterphaseProphaseChromosomeEarly metaphaseSpindle fibersChromosomeCentromereMetaphaseEarly anaphaseLate anaphaseEarly telophaseTelophaseCentrioles12345678(resting state prior to cell division)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Internal StructuresEndoplasmic reticulum two types:

Rough endoplasmic reticulum (RER) rough due to ribosomes; proteins synthesized and shunted into the ER for packaging and transport; first step in secretory pathway

Smooth endoplasmic reticulum (SER) closed tubular network without ribosomes; functions in nutrient processing, synthesis, and storage of lipids*

Rough endoplasmic reticulum*(a)(b)(c)RER membranemRNARibosomeProtein being synthesizedSmall subunitLarge subunitCisternaPolyribosomesPolyribosomesCisternaNuclear envelopeNuclear poreCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Internal StructuresGolgi apparatus

Modifies, stores, and packages proteins

Consists of a stack of flattened sacs called cisternae

*Transport vesiclesEndoplasmic reticulumCondensing vesiclesCisternaeCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

**Internal StructuresTransport Processes

Transitional vesicles from the ER containing proteins go to the Golgi apparatus for modification and maturation

Condensing vesicles transport proteins to organelles or secretory proteins to the outside

nucleus RER Golgi vesicles secretionRibosome partsCell membraneSecretory vesicleSecretion by exocytosisNucleusRough endoplasmic reticulumTransitional vesiclesGolgi apparatusCondensing vesiclesNucleolusCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Internal StructuresLysosomesVesicles containing enzymes that originate from Golgi apparatus Involved in intracellular digestion of food particles and in protection against invading microbesVacuolesMembrane bound sacs containing particles to be digested, excreted, or storedPhagosome vacuole merged with a lysosome*Food vacuoleLysosomeMerger oflysosome and vacuolePhagosomeDigestionDigestive vacuoleEngulfment of foodFormation of food vacuoleGolgi apparatusFood particleLysosomesCell membraneNucleusCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Inner membraneCircular DNA strandMatrixCristae(a)Outer membrane70S ribosomesInternal StructuresMitochondriaFunction in energy productionConsist of an outer membrane and an inner membrane with folds called cristaeCristae hold the enzymes and electron carriers of aerobic respirationContain DNA and prokaryotic ribosomes

*Cristae (darker lines)Matrix (lighter spaces)(b) Don Fawcett/Visuals UnlimitedCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Internal StructuresChloroplastConvert the energy of sunlight into chemical energy through photosynthesisFound in algae and plant cellsContains, thylakoids, stacked into granaPrimary producers of organic nutrients for other organisms*70S ribosomesCircular DNA strandGranumThylakoidsChloroplast envelope (double membrane)Stroma matrixCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Internal StructuresRibosomesComposed of rRNA and proteinsScattered in cytoplasm or associated with RERLarger than prokaryotic ribosomesFunction in protein synthesis*RER membranemRNARibosomeProtein being synthesizedSmall subunitLarge subunitCisternaCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Cell membraneRibosomesRough endoplasmic reticulumMicrotubuleMicrofilamentsMitochondrion(a)Internal StructuresCytoskeletonFlexible framework of proteins, microfilaments and microtubules form network throughout cytoplasmInvolved in movement of cytoplasm, amoeboid movement, transport, and structural support

*(b)Courtesy of Life Technologies, Carlsbad, CACopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Comparing Prokaryotes, Eukaryotes & Viruses*

Phylogenetic Relationships between Eukaryotes*Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.NaegleriaEntamoebaEuglenaTrypanosomaPhysarumVainmorphaTrichomonasGiardiaEncephalitozoonDictyosteliumBabesiaPorphyraCoprinus (mushroom)Zea (corn)AchlyaCostariaParameciumCryptomonasHomoEukarya(a)EVOLUTIONARY ADVANCEMENT OF THE EUKARYOTESAnimalsTrue Fungi(Eumycota)PlantsStramenopiles(formerly heterokonts or chrysophytes)Golden-brown and yellow-green algaXanthophytesBrown algaeDiatomsWater molds (Oomycota)CiliatesColponemaDinoflagellatesHaplosporidiaApicomplexansEntamoebidsAmoeboflagellatesKinetoplastidsEuglenidsParabasilids (Trichomonas)Diplomonads (Giardia)OxymonadsMicrosporidiaMetazoaMyxozoaChoanoflagellatesZygomycotaKingdom AnimaliaKingdom EumycotaKingdom PlantaeKingdom Protista Division ChlorophytaDivision RhodophytaDivision ChrysophytaDivision Phaeophyta Division BacillariophytaDivision EuglenophytaPhylum SarcomastigophoraPhylum CiliophoraDivision PyrrophytaPhylum ApicomplexaTraditional Kingdoms and SubcategoriesTaxonomy Based on mRNA AnalysisAscomycotaBasidiomycotaChytridiomycota (chytrids)Land plantsGreen algaeCryptomonadsRed algaeAlveolatesEntamoebaeUniversal AncestorLackmitochondriaPhylum Sarcomastigophora(b)

Survey of Eukaryotic MicrobesFungiAlgaeProtozoaParasitic worms*

Kingdom Fungi100,000 species divided into 2 groups:Macroscopic fungi (mushrooms, puffballs, gill fungi)Microscopic fungi (molds, yeasts)

* George Barron, University of Guelph, CANADACopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Microscopic FungiExist in two morphologies:Yeast round ovoid shape, asexual reproductionHyphae long filamentous fungi or moldsSome exist in either form dimorphic characteristic of some pathogenic molds*Septum Dr. Judy A. Murphy, San Joaquin Delta College, Department of Microscopy, Stocton, CAJanice Carr/CDCCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fungal NutritionAll are heterotrophicMajority are harmless saprobes living off dead plants and animalsSome are parasites, living on the tissues of other organisms, but none are obligate Mycoses fungal infectionsExtremely widespread distribution in many habitats*(a)(b) Kathy Park Talaro New Zealand Dermatological SocietyCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fungal OrganizationYeast soft, uniform texture and appearance Reproduce through an asexual process called budding

*Janice Carr/CDCFungal (Yeast) Cell(a)RibosomesMitochondrionEndoplasmic reticulumNucleusNucleolusCell membraneGolgi apparatusCell wallStorage vacuoleBud scarBudCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.BudNucleusBud scarsPseudohypha(c)(b)

SeptaSeptate hyphaeNucleusNucleiSeptum with poresAs in PenicilliumAs in RhizopusNonseptate hyphaeCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.**Fungal OrganizationFilamentous fungi mass of hyphae called mycelium; cottony, hairy, or velvety textureHyphae may be divided by cross walls septateVegetative hyphae digest and absorb nutrientsReproductive hyphae produce spores for reproduction

Fungal ReproductionPrimarily through spores formed on reproductive hyphaeAsexual reproduction spores are formed through budding or mitosis; conidia or sporangiospores

* George Barron, University of Guelph, CANADA(a) Vegetative Hyphae(b) Reproductive HyphaeSurfacehyphaeSubmergedhyphaeHyphaGerm tubeRhizoidsSporeSubstrateSpores(c) GerminationCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.(d)

*Types of Asexual Mold SporesArthrosporesChlamydosporesPhialosporesPorosporeMicroconidiaMacroconidiaSporangiophoreSporangiosporeColumellaSporangium 1 4 5 1 2 2 3ConidiaSporangiosporeSterigmaConidiophoreBlastospores(a)(b)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chytrid cellsDiatom cell10.0 mmDiversity of Fungi* Kathy Park Talaro George Barron, University of Guelph, CANADA George Barron, University of Guelph, CANADA Gregory M. Filip Joyce E. Longcore, University of MaineCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Roles of FungiAdverse impactMycoses, allergies, toxin productionDestruction of crops and food storagesBeneficial impactDecomposers of dead plants and animalsSources of antibiotics, alcohol, organic acids, vitaminsUsed in making foods and in genetic studies

*

*Human Fungal Infections

The ProtistsAlgae - eukaryotic organisms, usually unicellular and colonial, that photosynthesize with chlorophyll aProtozoa - unicellular eukaryotes that lack tissues and share similarities in cell structure, nutrition, life cycle, and biochemistry*Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.EVOLUTIONARY ADVANCEMENT OF THE EUKARYOTESAnimalsTrue Fungi(Eumycota)PlantsStramenopiles(formerly heterokonts or chrysophytes)Golden-brown and yellow-green algaXanthophytesBrown algaeDiatomsWater molds (Oomycota)CiliatesColponemaDinoflagellatesHaplosporidiaApicomplexansEntamoebidsAmoeboflagellatesKinetoplastidsEuglenidsParabasilids (Trichomonas)Diplomonads (Giardia)OxymonadsMicrosporidiaMetazoaMyxozoaChoanoflagellatesZygomycotaKingdom AnimaliaKingdom EumycotaKingdom PlantaeKingdom Protista Division ChlorophytaDivision RhodophytaDivision ChrysophytaDivision Phaeophyta Division BacillariophytaDivision EuglenophytaPhylum SarcomastigophoraPhylum CiliophoraDivision PyrrophytaPhylum ApicomplexaTraditional Kingdoms and SubcategoriesTaxonomy Based on mRNA AnalysisAscomycotaBasidiomycotaChytridiomycota (chytrids)Land plantsGreen algaeCryptomonadsRed algaeAlveolatesEntamoebaeUniversal AncestorLackmitochondriaPhylum Sarcomastigophora

AlgaePhotosynthetic organismsMicroscopic forms are unicellular, colonial, filamentousMacroscopic forms are colonial and multicellularContain chloroplasts with chlorophyll and other pigmentsCell wallMay or may not have flagella*RibosomesFlagellumCytoplasmNucleusNucleolusGolgi apparatusCell membraneMitochondrionStarch vacuolesCell wallChloroplastAlgal Cell(a)(b) Jan Hinsch/Photo Researchers, IncCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

AlgaeMost are free-living in fresh and marine water planktonProvide basis of food web in most aquatic habitatsProduce large proportion of atmospheric O2Dinoflagellates can cause red tides and give off toxins that cause food poisoning with neurological symptoms

*

*Algae ClassificationClassified according to types of pigments and cell wallUsed for cosmetics, food, and medical products

ProtozoaMost are harmless, free-living in a moist habitatSome are animal parasites and can be spread by insect vectorsAll are heterotrophic lack chloroplastsFeed by engulfing other microbes and organic matter

*

ProtozoaMost have locomotor structures flagella, cilia, or pseudopodsExist as trophozoite motile feeding stageMany can enter into a dormant resting stage when conditions are unfavorable for growth and feeding cystAll reproduce asexually, mitosis or multiple fission; many also reproduce sexually conjugation*Trophozoite is reactivated.Trophozoite (active, feeding stage)Cell rounds up, loses motility.Cyst wall breaks open.Mature cyst (dormant, resting stage)Early cyst wall formationCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Moisture,

nutrients restoredDrying, lack

of nutrients

Protozoan IdentificationClassification is difficult because of diversitySimple grouping is based on method of motility, reproduction, and life cycleMastigophora primarily flagellar motility, some flagellar and amoeboid; sexual reproductionSarcodina primarily amoeba; asexual by fission; most are free-livingCiliophora cilia; trophozoites and cysts; most are free-living, harmless Apicomplexa motility is absent except male gametes; sexual and asexual reproduction; complex life cycle all parasitic

*

*MastigophoraProtozoan Cell(a)Cell membraneGlycocalyxRibosomesMitochondrionEndoplasmicreticulumNucleusPellicleNucleolusCell membraneGolgi apparatusWater vacuoleCentriolesFlagellumCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.(b)Janice Carr/CDC

*Sarcodina*NucleusFood vacuolesContractile vacuolesPseudopods(a)(b) David Patterson/MBL/Biological Discovery in Woods Hole

*Ciliophora*(a)Oral cilia in grooveGulletFood vacuolesMacronucleusMicronucleusWater vacuole Eric Russell, BioMEDIA ASSOCIATESCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Yuuji Tsukii, Protist Information Server(b)

*Apicomplexa*(a)Cytostome (mouth)Food vacuoleEndoplasmic reticulumNucleusCell membraneMitochondrionCytostomeFood vacuolesNucleus(b)Michael Riggs et al, Infection and Immunity, Vol. 62, #5, May 1994, p. 1931 ASMCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Pathogenic Protozoa*

Important Protozoan PathogensPathogenic flagellatesTrypanosomes TrypanosomaT. brucei African sleeping sicknessT. cruzi Chagas disease; South America

*(a) Infective Trypanosome(b) Mode of infectionCycle in the WildReduviid bugCycle in Human DwellingsCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

**Important Protozoan PathogensInfective amoebasEntamoeba histolytica amebic dysentery; worldwideCysts in food, water(a)Trophozoites released(b)Large intestine site of infectionEatenFood, waterFecesCysts exitMature cystsSmall intestineMaturetrophozoitesStomach(c)(d)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Parasitic HelminthsMulticellular animals, organs for reproduction, digestion, movement, protectionParasitize host tissuesHave mouthparts for attachment to or digestion of host tissuesMost have well-developed sex organs that produce eggs and spermFertilized eggs go through larval period in or out of host body*

Major Groups of Parasitic HelminthsFlatworms flat, no definite body cavity; digestive tract a blind pouch; simple excretory and nervous systemsCestodes (tapeworms)Trematodes or flukes, are flattened, nonsegmented worms with sucking mouthpartsRoundworms (nematodes) round, a complete digestive tract, a protective surface cuticle, spines and hooks on mouth; excretory and nervous systems poorly developed*

Helminth Classification and IdentificationClassify according to shape, size, organ development, presence of hooks, suckers, or other special structures, mode of reproduction, hosts, and appearance of eggs and larvaeIdentify by microscopic detection of worm, larvae, or eggs*EsophagusVentral suckerCuticleUterusTestes(b)(a)ScolexCuticleProglottidFertile eggsImmature eggsSuckersPharynxIntestineVas deferensOvarySeminal receptacleExcretory bladderOral suckerCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Distribution and Importance of Parasitic WormsApproximately 50 species parasitize humansDistributed worldwide; some restricted to certain geographic regions with higher incidence in tropicsAcquired through ingestion of larvae or eggs in food; from soil or water; some are carried by insect vectorsAfflict billions of humans*

Lifecycle of the Pinworm*Cross-infectionSelf- infectionFertile eggFemaleAnusCopulatory spiculeMaleEggsMouthCuticleMouthAutoinoculationCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

***********************************************