Microbio Exam 2: Bacteria motility (Flagella, Taxis, Endoflagella, etc.)
Endoflagella (basic)
flagella found inside cell, but looks like it is outside of cell
Flagella: What is it? Basic function?
long, semi rigid & filamentous appendage; aids in motility-- - acts as spinning motor, propels cell in forward motion - Flagella motility uses a great amount of energy (2/3 or more of energy generated is used; like swimming in murky olympic size pool or car moving 670 mph)
Runs/Tumbles re: Attractant
more runs of longer duration and less tumbles
Runs/Tumbles re: Repellent
more tumbles
Unfavorable stimulus produces what kind of taxis?
negative taxis
Favorable stimulus produces what kind of taxis?
positive taxis
Taxis
sensing and responding to stimuli/environment
Monotrichous flagella arrangement with example
single polar flagella Ex: Pseudomonas aeroginosa
What kind of bacteria has endoflagella
some spirochetes; Ex: Borrelia, T. palladium, Listeria (Lyme, Syphilis, Listeria)
Tumbles
sudden stop of movement, cell rolls over several times, changes direction and resumes run
Amphitrichous flagella with example
tuft of flagella at each end of cell; work in unison Ex: Spirillum volutans "Amphi"dexterous: use both sides
Lophotrikhous flagella with example
two or more flagella at one pole of cell (at one end of the cell) Ex: Helicobacter pylorii: helps bacteria to invade across the mucosal coating of the intestinal epithelium (virulence factor)- causes ulcers L: Lop sided (only on one side)
Runs
uninterrupted sustained unidirectional movement
Two bacterias that have endoflagella
Lyme (Borrelia burgdorferi) Syphilis (Treponema palladium)
Hook
Wider part of Flagella to which the filament is attached; made of protein (NOT flagellin)
Endoflagella characteristics
- present in spirochetes - there is an outer sheath (membrane) below which are fibrils (axil filaments) - sheath is anchored at one end and spirals around cells - uses cork screw motion to drill into viscous tissues of their host. this allows them to go deeper
How much of the energy produced by a bacterial cell is used for flagella motility?
2/3 or more
Spirillum volutans has what kind of flagella arrangement?
Amphitrichous- tuft of flagella on either end that work in unison
Basal Body
Anchors flagellum to the cell wall and PM; includes central rod inserted into a series of rings; Gram + has 1 pair of rings Gram - has 2 pairs of rings (inner & outer - inner rings attached to PM, outer rings attached to outer membrane); Rotation is either clockwise or "anti clockwise" along its axis
Where is the axis from which the spinning motion happens?
Basal Body of Flagella
Chemotaxis
Chemical component acts as stimulus; Attractant ex: nutrient (cells move toward it; positive taxis) Repellent ex: toxin (cells move away from it; negative taxis)
One type of taxis
Chemotaxis: chemical component acts as stimulus
What kind of bacteria have a peritrichous flagella arrangement?
E. coli
Three main parts of Flagella:
Filament, Hook, Basal body
Peritrichous flagella with example
Flagella distributed over entire surface Ex: E. coli P: Pretty pieces of hair all over
Flagellin
Globular protein which makes up the Filament of the Flagella
3 external features that help bacteria respond to other cells and their environment?
God Please F*** Forever Glycocalyx, Pili, Flagella, Fimbriae
How many pairs of rings are found in the Gram + Basal body of the Flagella? In the gram -?
Gram + has 1 pair of rings Gram - has 2 pairs of rings (inner & outer: inner rings attached to PM, outer rings attached to outer membrane)
What is special about the Helicobacter pylorii regarding Flagella?
H. pylorii has Lophotrikhous flagella which help the bacteria to invade across the mucosal coating of the intestinal epithelium. They have evolved to survive well in the stomach and push through mucosal barrier (which is very thick and hard to cross). They cause ulcers. The flagella is considered a virulence factor.
What is an example of a bacteria with a lophotrichous flagella arrangement?
Heliobacter pylorii
Filament
Long "whip like" structure of constant diameter; no membranous covering; structural component is Flagellin (globular protein)
Heliobacter pylorii has what kind of flagella arrangement?
Lopho-trichous: several on one end
Flagella arrangement
Marissa's Payment Almost Late Monotrichous, Peritrichous, Amphitrichous, or Lophotrichous
Pseudomonas aeroginosa has what kind of flagella arrangement?
Monotrichous- one single flagella at one end
E. coli has what kind of flagella arrangement?
Peritrichous
Name a bacteria that has a monotrichous flagella arrangement:
Pseudomonas aeroginosa
One example of a bacteria with an amphitrichous flagella arrangement
Spirillum volutans
How does the Flagella work as a spinning motor? Which way does it move? Which way does the bacteria move in response?
The flagella moves in a clockwise or counter clockwise fashion and always propels the bacteria forward.
