Unit 1: Lecture 5: Bacterial Flagella
_____________________ and ____________________ also allows some spirochetes to enter and exit blood vessels in order to disseminate in the body.
*Motility* and *Chemotaxis*
______________________ and ____________________may enable some bacteria to swim through mucus in order to make contact with host cells.
*Motility* and *Chemotaxis*
__________________ enable the spirochetes to penetrate tissues as well as enter the lymphatics and bloodstream enabling their dissemination to other body sites.
*Motility, Chemotaxis,* and *Invasins*
Humans are the ONLY *natural host*.
*Treponema pallidium*
Typically transmitted *sexually* by contact with infected lesions; may be transmitted congenitally.
*Treponema pallidium*
________________ _________________ is a spirochete 0.1 µm X 5-15 µm.
*Treponema pallidium*
A *Bacterial flagellum* consists of:
1. A *filament* 2. A *hook* 3. A *basal body*
A single flagellum at *both ends* of the organism.
Amphitrichous
Internal flagella found *only in the spirochetes.*
Axial filaments
Most bacteria with *polar flagella*, can rotate their flagella:
BOTH *Clockwise* and *Counterclockwise*.
In bacteria with *polar flagella*: When it rotates *clockwise*, it pulls the bacterium _____________________.
Backward
The ____________________ ___________________ consists of a *filament* that extends from the cell surface, a *basal body* that anchors the filament to the bacterium and functions as a *molecular motor*, and a *flexible hook* that couples the filament to the basal body.
Bacterial flagellum
The ______________ _____________ consists of a rod and a series of rings that anchor the flagellum to the cell wall and the cytoplasmic membrane.
Basal body
The _____________________ is the rigid, helical structure that extends from the cell surface.
Filament
The __________________ of bacterial flagella is a *PAMP* that binds to *PRRs* on defense cells to *initiate innate immunity.*
Flagellin
In bacteria with *polar flagella*: If the flagellum is rotating *counterclockwise*, it pushes the bacterium ________________.
Forward
The ____________ is a flexible coupling between the filament and the basal body
Hook
*Two or more* flagella at *one or both* poles.
Lophotrichous
A single flagellum, usually at *one pole*.
Monotrichous
Flagella over the *entire surface*
Peritrichous
*Energy* for *rotation* comes from the:
Proton motive force
In bacteria with *polar flagella*: These bacteria change *direction* by changing the:
Rotation of their flagella
What is the infection *Treponema pallidium* causes?
Syphilis
A motile response to an environmental stimulus.
Taxis
If a bacterium has a peritrichous arrangement of flagella, ________________ of the flagella causes them to form a single bundle that propels the bacterium in long, straight or curved runs without a change in direction.
counterclockwise
*Internal flagella*, or *axial filaments*, are seen only in:
spirochetes
The overall function of bacterial flagella is:
to keep bacteria in an optimum environment via taxis.