2.6 Flashcards
motility
ability to propel own movement
whats weird about yersinia pestis and motility
most yersinia are motile but not this, even when it has genes for it
flagellum
long thin filament that acts like a propeller, rotated using motor that is anchored in the cell envelope
what are the two uses of flagellum
swimming and swarming (required multiple bacteria)
different arrangement of flagellum
peritrichous- many across pole/ body
monotrichous(or polar) - single
lophotrichous- many at one pole
amphitrichous- both poles
atrichous - no flagella
counterclockwise movement in peritrichous
-a “run”, helical rotation formed at tail and cell goes forward
-long
Clockwise
a tumble, helical bundle falls apart and cell assumes random direction
monotrichous bacteria include
those with reversible flagellum: can go back and forth
unidirectional flagella- goes only straight and reorients randomly
flagella segments
filament
hook
basal body
flagellar motor
20 proteins anchored in CM and CW
-harness proton motive force
what does the central rod do in flagellar motor
connection
passes through MS ring(CM), the C ring(cytoplasm), the P ring (peptidoglycan) and the L ring (outer memb)
what does C ring do in flagellar motor
generating torque, switch motor direction, secrete flagellin
what do L/ P rings do
act like bearing and cut back on friction during rotation
what does MS ring do
rotate the rod that rotates the hook and filament
what does the Stator do
is the “turbine”, couples the flow of protons to the rotation of the MS ring
what is the difference b/w gram +ve and g -ve flagellum
g +ve lacks P/L rings(bearing), has C/ MS rings
what are the proteins that make up the flagellar filament
flagellin, lots of it
flagellar filament characteristics
5-10 mewM long, 20nm wide
rigid to maintain shape, helical to act like a screw driver and act like less of a whip, and is hollow
what does flagella connect to
free at one end and connected to motor at other
what is conserved in bacterial flagella
flagellin as filament, but sequence varies
why does sequence for flagella vary
because it can be detected by immune systems,
what is the important Antigen associated with flagellum
H antigen, i think that means thatwe detect H antigen> idk
synthesis of flagellum
built inside out
-motor and inner stuff assembles faster
-filament grows from outside
how is filament produced
produced in cytoplasms and secreted through flagellum via hollow filament, subunit assembles at end helped by cap proteins
