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Eukaryotic Microorganisms - Chapter 12 From Biol 131 - You are expected to read and understand the fundamental characteristics of eukaryotic and prokaryotic cells (see Chapter 3 of the Bauman text) Not responsible for all the detailed characteristics of the microbes (such as different fungal sexual reproduction) used for their taxonomic classification – only what is presented in class Be sure to read sections in other chapters about example diseases and pathogens Eukaryotes1
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2 How are eukaryotes classified? What are the distinguishing characteristics of “algae, “protozoa” and “fungi”?
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Eukaryotes3 How can we explain the origins of different photosynthetic protists? Review Endosymbiosis from Biol 131 -- see end of Chapter 3
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Eukaryotes4 Characteristics of Protozoa heterotrophic or 2 O Ps no cell wall cytosome contractile vacuole most are motile some stalked some have multiple nuclei
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Eukaryotes5 Kinetoplastids -- have weird mitochondrial DNA Some are important pathogens Trypanosoma (see chap 20) African sleeping sickness -- trypanosomiasis -- Tse-tse fly Chagas disease -- American trypanosomiasis Dinoflagellates -- Chloroplasts via 2 O endosymbiosis -- phytoplankton Pfiesteria -- neurotoxin -- red-tides See EPA site on Pfiesteria and red tides http://ivy3.epa.gov.tw/OMISAR/Data/OMISAR/prjdoc/bam1.3/Pfiesteria.html Dinoflagelate
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Eukaryotes6 Amoebas Most common – indefinite form Extend ‘pseudopeds’ A few are pathogenic e.g., Entamoeba sp Foraminifera form outer “shell” e.g., Can be ‘huge’ (mm’s) Fossil markers Foraminiferan Amoeba Amoeba feeding
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Eukaryotes7 Aveolates -- have aveolar sacs below membrane Ciliates Cilia functions: Locomotion Feeding 2 nuclei Apicomplexans “apical complex” of microtubules Contractile vacuole Stentor feeding
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Eukaryotes8 Plasmodium causes Malaria (chapt 21) (Apicomplexan) Visit CDC web site http://www.cdc.gov/MALARIA/disease.htm Anopheles mosquito Complex life cycle sporozoites trophozoites merizoites Sexual reproduction Disease children adults Treatment Plasmodium Life Cycle
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Eukaryotes9 What are the key characteristics of Algae -- photosynthetic -- cell wall Great diversity in.. -- pigmentation -- origin of C’plasts -- cell structure And in organism structure -- unicellular -- filamentous -- colonial -- multicellular Red alga (Rhodophyta)
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Eukaryotes10 Classification of Algae Primary Symbionts Chlorophyta Rhodophyta Secondary Symbionts Euglenoids Chrysophyta Dinoflagelates Phaeophyta
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Eukaryotes11 Why are Chlorophyta believed to be the evolutionary precursors of the higher plants? - Cell wall structure - Chloroplast structure - Photosynthetic process and products
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Eukaryotes12 Euglenoids and Diatoms -- 2 O endosymbiosis Euglenoids -- light senstitive ‘eye spot’ Diatoms (Chrysophyta) - Silcaceous cell walls Diatoms
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Eukaryotes13 Rhodophyta (1 O endosymbiosis) Phaeophyta (2 O endosymbiosis) -- common “marine macroscopic algae” -- specialized structures Colors vary widely Pigments optimized for light abs Chondrus crispus
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Eukaryotes14 Components of Rhodophyta cell walls are sources of thickening agents -- Agar (Gelidium) -- Alginates (var. sources) -- Carrageenan (Chondrus crispus) In foods, industrial, pharmaceuticals applications -- syrups, ice cream, candies, jams… -- paints, adhesives, paper coatings,… -- creams, shampoos, capsules etc … Algae are very important as producers of ecosystems -- phytoplankton -- macroscopic algae Involved in symbiotic relationships -- invertebrates -- lichens
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Eukaryotes15 Fungi ( Mycology) Read section in book thoroughly Basic Characteristics -- cell walls (chitin) -- heterotrophic Common Shapes Yeasts (spherical) e.g., Saccharomyces Molds (filamentous) hyphae mycelium Dimorphism is common
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Eukaryotes16 How do fungi reproduce? Asexual budding spores & sporangia Sexual ‘+’ and ‘-’ types mushrooms Budding yeasts
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Eukaryotes 17 How are Fungi Classified? Characteristics of sexual reproduction structures Ascomycota -- e.g., Penicillium; morels Saccharomyces Basidiomycota -- e.g., Rusts; Coprinus Zygomycota -- e.g., Rhizopus Or based on other traits Glomeromycota -- mycorrhizal fungi Read more thorough descriptions of fungal groups in text. Note: Deuteromycota is no longer a recognized fungal group.
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Eukaryotes18 Ecology & Nutrition Decomposers Symbiosis mycorrhizae lichens Predators?? -- nematophagus fungi -- Arthrobotrys (ascomycota) Vid 1 Vid 2 Vid 3
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Eukaryotes19 Entomophagus Fungi Cordyceps (ascomycota) is important pathogen of insects Cordyceps
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Eukaryotes20 Fungi as Plant Pathogens Agricultural threats ‘Rust diseases’ Dutch elm disease Ophiostoma ulni (Ascomycota) Other Impacts on Humans Ergot poisoning Claviceps (Ascomycota) mycotoxins Irish potato famine Phytophthora infestans (Alveolata) American Elms before and after Dutch elm blight (Minnesota Department of Agriculture)
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Eukaryotes21 In 1940s, Marietta had approximately 2000 American elm trees. How many remain in 2014?
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Eukaryotes22 Trychophyton rubrum Fungal human pathogens “Mycoses” (Chap 19) (cutaneous vs systemic) Trychophyton rubrum -- Ascomycota -- associated with many Tineas tinea capitis (“ringworm”) tinea pedis tinea cruris Candida albicans -- Ascomycota -- mucus membrane / vaginal infections -- AIDS Treatments -- challenging -- Ergosterol metabolism Wiki on antifungals: http://en.wikipedia.org/wiki/Antifungal_drug candidiasis Candida albicans
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Eukaryotes23 Fungi pathogens, con’t. Subcutaneous / Systemic -- some endemic to our area Blastomycosis See Chap 22 & CDC web page Pulmonary Blastomycosis See CDC web page: http://www.cdc.gov/fungal/diseases/blastomycosis/index.html
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