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20 Cards in this Set
- Front
- Back
Characteristics of Prokaryotes
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Exterior:
Cell wall- outer membrane and peptidoglycan layer that gives structures Plasma membrane Flagellum- some, not all Capsule- slime layer Interior: Ribosomes- units that help make proteins Nucleiod- DNA Cytoplasm- ions, H2O, etc. |
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Prokaryotes are found...
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free-living, parasitic, biofilms
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Biofilms
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Community of micro-organisms that adhere to a surface
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Prokaryotes are successful because...
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Have distinctive cell walls- gram neg/pos
Locomotive- nutrition/protection Fast reproduction- binary fission Communication- bioluminescence Diverse metabolism- photoautotrophs, photoheterotrophs, chemolithotrophs, chemoheterotrophs |
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Gram positive
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Stain purple
Outside of cell, thick peptidoglycan layer, plasma membrane, inside of cell |
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Gram negative
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Stain pink
Outside of cell, outer membrane, thin peptidoglycan layer, plasma membrane, inside of cell |
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Photoautotrophs
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Light as energy source, CO2 as carbon source
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Photoheterotrophs
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Light as energy source, CO2 or other compounds as carbon source
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Chemolithotrophs
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Inorganic substances for energy, CO2 as carbon source
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Chemoheterotrophs
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Organic substances for energy, organic compounds for carbon
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Diversity of Prokaryotes
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Bacteria:
Spirochetes, Chlamydias, High-GC gram positive, Cyanobacteria, Low-GC gram positive, Proteobacteria Archaea: Crenarchaeota, Euryarchaeota |
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Spirochetes
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• Gram negative
• move via ‘axial filaments’ • Borellia burgdorferi ~ ‘Lyme disease’ |
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Chlamydias
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• smallest bacteria
• only live as parasites in other cells • e.g. Trachoma- can blind children • e.g. “the clap” a.k.a. Chlamydia |
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High-GC gram positive-
Actinobacteria |
Thick peptidoglycan layer- stains purple
Lots of GCs vs. ATs Most are free living in the soil Some cause disease e.g. Mycobacterium tuberculosis which causes human tuberculosis ( “ t.b.” ), and kills about 3 million people a year. |
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Low-GC gram positive
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Thick peptidoglycan layer- stains purple
Less GCs vs. ATs Produce endospores- hard heat resistant capsules e.g. Bacillus thuringiensis- bug spray for veggies Anthrax- stays dormant for years in soil |
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Cyanobacteria
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Blue-green algae (rest of algae are eukaryotic)
Responsible for the production of oxygen on early earth Use chlorophyll for photosynthesis |
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Proteobacteria
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Gram negative “purple bacteria”
Many modes of nutrition Rhizobium- nitrogen fixing bacteria in root nodules of legumes, transfers atmospheric N2 to plant friendly N- gets sugar and a home in return |
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How are archaea different from bacteria?
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1. no peptidoglycan in cell walls
2. distinct lipid composition in cell membranes |
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Crenarchaeota
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"Extremophiles" Live in hot, salty, toxic places like deep sea thermal vents
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Euryarchaeota
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"Methanogens" - One third of atmospheric methane (a
greenhouse gas), is created as a by-product of Archaean metabolism - Interesting example: Bacteria in the gut of protozoans which live inside termites are methanogens, and they help the termites to break down wood. |