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Domain Archaea
- Prokaryotic-Lack nucleus
- More resistant to heat and other extreme
- Found in moderate conditions
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Extremophiles
- Occupy habitats with very high salt content, acidity or methane levelsm or high temperatures.
- Methanopyrus grows in deep sea thermal vents at 98 C-Hyperthermophile
- Sulfolobus grows in hot springs at pH 3
- Halophiles
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Domain Bacteria
- 50 or so bacterial phyla-Structural and metabolic features of half unknown
- Some are extremeophiles but many more bacteria favor moderate conditions
- Form symbiotic relationships with eukaryotes
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Cyanobacteria
- Photosynthetic bacteria abundant in fresh waters, oceans and wetlands and on surface of arid soils
- Named for blue-green (cyan) color
- Only prokaryotes that generate
- Gave rise to plastids of eukaryotic algae and plants
- Display greates structual diversity found among bacterial phyla
- Essential ecological roles in producing organic carbon and fixing nitrogen
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Eukaryotic nucleus and cytoplasm
likely arose in an ancient archaeal organism
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Mitochandria and plastids
orginated from proteobacteria and cyanobacteria by endosymbiosis
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Bacteria and Archaea
- Share small size, rapid growth and simple cellular structure
- Are 1-5um in diameter
- limits the amt of materials that can be stored within cells but allows faster cell division
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What are the five major shapes?
- Spheres- cocci
- Rods- bacilli
- Comma-Shaped- vibrios
- Spiral-shaped Spirochaetes r flexible & spirilli r rigid
Some occur as single cells, pairs and filaments
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Mucilage
- Sometimes called Glycocalyx
- Composed of polysacc., protein or both
- Secreted from cells
- Fxn: Evade host defenses
- Hold colony together
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Cell-Wall Structure
- Most hv rigid cell wall outside the PM
- Maintain cell shape and help protect agant attack
- Help to avoid lysis in hypotonic soltion
Archaea and some bacteria use protein where as most bacteria use peptidoglycan
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What is gram positive?
- Thick peptidoglycan layer
- Purple dye held in thick layer
- Cells are stained purple
- Vulnerable to pencillin that interferes in cell wall synethesis
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What is gram negative?
- Less peptidoglycan and a thin outer envelope of lipopolysac.
- Lose purple stain but retain final pink stain
- Cells are stained pink
- Resists pencillin and requires other antibios'
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What is their motility?
- Move to favorable conditions
- Respond to chemical signals
Switch, twitch, glide or adjust floatation
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What is Flagella?
- Swimming
- Different in eukaryotic flagella
- Like an outboard boat motor
- Differ in number and location of flagella
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What is Pili?
- Twitch or glide across surface
- Threadlike cell surface structures
- Play import roles in bacterial reprod and dz processes
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What is binary fusion?
divide by splitting in two
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What is Akinetes?
- Found in aquatic filamentous cyanbact
- Develop when winter approaches
- Survive winter and produce new filaments in spring
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What is Endospores?
- Tough protein coat
- Amazingly long dormant span
- Found in some Gram-pos bacteria
IE: Bacillus antracis, Clostridium botulinum, Clostridium tetani
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How they obtain their genetic material?
- Transduction: Via viral vector
- Transformation: Via uptake of DNA from environment
- Conjugation: Via mating with another cell
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What is Autotrophs?
Produce all or most of their own organic compounds
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What is Photoautotroph?
Use light as energy source for synthesis of organic compds frm CO2 or H2S.
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What is Chemoautotrophs?
Use energy obtained from chemical modification of inorganic compds to synthesize organic compds
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What is Heterotrophs?
Organisms that require at least one organic compd and often more
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What is Photoheterotroph?
Able to use light energy to make ATP but they must take in organic compds from the envirnmt
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What is Chemoorgantroph?
Must obtain organic molecules for both energy and carbon source.
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What is Obligate?
Require oxygen
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What is Facultative aerobes?
can use oxygen or not
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What is Obligate Anaerobes?
cannot tolerate oxygen
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What is Aeortorlerant anaerobes?
Do not use oxygen but are not poisoned by it
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What is envoles of Carbon cycle?
- Producers synthesize organic compds used by other organisms as food
- Decomposers break down dead organisms to release minerals for reuse
- Methanogens-makes methane
- Methanotrophs- consume methane
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What is Symbosis
An organism that lives in close association with one or more other organisms
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What is Parasitism?
One partner benefits at the expense of the other
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What is Mutualism?
Association beneficial to both partners
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What is Syntrophy?
Some bacteria live together and supply each other with essential nutrients
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What is Consortia?
Larger community of nutrient exchangers.
IE: Marine worm with no mouth, gut, or anus depends on bacteria inside it for food and waste recycyling
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Associations with Eukaryotes
- Bacteria induces normal development in Ulva
- Bioluminescent bacteria in squid and other animals
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