MIC 230: Motility
22 Cards in this Set
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structure of flagella
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long proteinaceous filaments, semi-rigid, rotates like propellar
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energy source for flagella
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bacteria: proton motive force
archaea: ATP
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Flagella Arrangement
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A- Monotrichous- 1
B- Lophotrichous- many at one end
C- Amphitrichous-both ends
D- Peritrichous- many everywhere
-bilophotricous: many on both ends
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Flagella Parts
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Basal Body: Embedded in cell, anchor
Hook: Flexible link between basal body and filament, swivels, how the filament is attached to basal body
Filament: Hollow cylinder of flagellin
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random walk
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a combination of running and tumbling...NOT LINEAR, alternates
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Temporal sensing
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A mechanism of gradient sensing used by bacteria in which the concentration of an environmental chemical is compared to the concentration at some previous time.
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Chemotaxis
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movement of bacteria in response to environmental stimuli
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other motilities
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-GLIDING: movement on surface
-GAS VACUOLES: positioning mechanism, spindle in appearance, inflate with air so rises, terger pressure bursts which causes them to sink
-SPIROCHETAL: uses endoflagella, corkscrews, works well in mucus, only in spirochetes
-TWITCHING: pili, contract …
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fimbrae
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used for attachment, shorter than flagella
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what composes the cytoplasm?
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small molecules
ribosomes/RNA
DNA
inclusion bodies
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small molecules
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solutes (ions, amino acids, sugars) enzymes
ribosomes (70s, grainy)
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ribosomes/RNA
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tRNA, mRNA, rRNA
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DNA
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closed circular molecule, supercoiled to fit in cell, some cells have plasmids (extra DNA, why resistant)
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inclusion bodies
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carbon and energy storage: carbon and energy(PHB large storage bodies glycogen and starch)
phosphate granules: refractile, energy storage
elemental sulfur
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other inclusions
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magnetosomes: allows cells to orient to magnetic field
gas vacuoles
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Endospores
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highly differentiated cells resistant to heat, harsh, chemicals, and radiation
"dormant" stage of bacterial life cycle
-only present in some GRAM POSITIVE BACTERIA
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who makes endospores??
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Clostridum, Bacillus
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purpose of endospores
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protect genetic information
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resistant and endospores
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very protected to boiling, chemicals, heat, UV
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problems with endospores
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double cell membrane=hard to destroy
food spoilage
botulism
tetanus
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structure of endospores
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double cell membrane
mother engulfs daughter cells
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life cycle??
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vegetative-->developing spore-->sporulating cell-->mature sport
*survival/resting NOT REPRODUCTIVE
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MIC 230: Motility