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Non-Prokaryotic microbes and viruses
- Eukaryotes typically 1-celled organisms
- Viruses important in microbe evolution due to horizontal gene transfer
- Viruses not considered to be alive
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Eukaryotic Cell Movement
- Movement w/in eukaryotes is both intra- and cellular
- movement dependent on microtubules in cilia and flagella
- cilia and flagella contain (9+2) arrangement of tubules
- Subcellular mvmt dependent on microtubules & Microfilament
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Eukaryotic Import Mechanism
- Endocytosis and Phagocytosis
- Endo: Used to recycle the CM
- Phago: Process for something really large
- Lysosomes contain hydrolytic enzymes
- Hard to occur in rigid cell walls
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Eukaryotic Microbes: Protist
- Non-fungi eukaryotic microbes
- consists of single celled organisms
- Current schemes based on DNA and biochemical analysis
- Divided into supergroups
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Super Group Archaeplastida
- Plastids: organelles dervided from photosythetic endosymbiotic bacteria
- Double membrane
- cyanobacteria gram (-)
- Cell walls contain cellulose
- Examples: Red and green algae
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Super Group Amebozoa
- Ameboid movement: uses lobopodia to move
- Some have cilia or flagella
- Dictyostelium Discoideum: widely studied as model for differentiation and cell signaling
- Pathogenic genera: Entamoeba (dysenthery) and Acanthamoeba (brain damage)
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Super Group Chromalveolata
- Have secondary plastids (engulfed algae instead of bacteria)
- Have more than 2 membranes
- Location w/in ER
- Includes coccoliths and diatoms
- Alveolata: Dinoflagellates (red tide), Apicomplexa (malaria), Ciliophora
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Alveolates (Subgroup of supergroup chromalveolata)
- Dinoflagellata (red tide): Contain potent neurotoxins. 2 flagella
- Ciliophora (Paramecium): Contain 2 different nuclei, contain micronucleus which contain 1000's of frequently transcribed genes
- Apicomplexan: All parasites. Apical complex allows microbe to penetrate into hosts. Disease include malaria and toxoplasmosis
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Diatoms and Coccoliths (members of supergroup chromalveolata
- Photosynthetic with external mineral shells
- Diatoms: Petri-dish like structure made out of silica. Fix as much CO2 as all rain forests combined
- Coccoliths: Made up of CaCO3. Found in high levels in plankton. regulate CO2 cycle. Major constituent of limestone
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Super Group Excavata
- Mostly pathogens
- Contain flagella that directs food into cytostome
- Leishmania: Flesh-eating disease (mostly in middle east)
- Giardia (Camper's diarrhea). 200 million infections
- **Trypanosoma Brucei: African Sleeping sickness. spread by tsetse flies
- **T. Cruzi: Causes chagas' disease-spread by kissing bugs
- **= should know
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FUNGI
- Yeasts (Microscopic), molds, mushrooms
- All non-photosynthetic, non-phagocytotic, Cell wall made of chitin.
- Bodies of fungi called Thalli
- Cellular Filaments called hyphae
- sexual cycle involves reversible mating types (A & Alpha)
- Can either be symbionts or parasites
- Saprobes/decomposers
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Reproduction in Fungi
- Sexual or nonsexual
- All form spores from either sexual or vegetative cells
- 2 haploid cells fuse in sexual cycles (2 nuclei)
- Type of sporulation used for classification
- Spores are mainly for dispersal, but can stand harsh environments
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Saccharomyces Cerevisiae (Yeast)
- Non-pathogenic
- Used to make recombinant proteins
- Have some regulation similar to multi-cellular eukaryotes
- Can grown in both haploid and diploid states
- Always ability to have 2 mating types
- Forms an ascus-contain 4 haploid spores
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Candida albicans (Yeast)
- Opportunistic pathogens
- Hard to get rid of once it is infected because it display dimorphic growth (Mycelial type growth)
- High mortality rate due to 100's of toxins produced
- Disease include thrush
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Fungal cancer-causing toxins-Aflatoxins and fumonisins
- Aflatoxins: Produced by aspergillus. Found in moist grains, nuts, beer, cocoa, raisins
- Fumonisins: Produced by Fusarium. Found in corn. Cause pulmonary edema in pigs. Esophogeal cancer in humans
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