Download Bacterial Flagellum-Rough Draft - mhs

Motor on the Move
By: Catherine Lawrence
A functioning motorboat with the ability to reach 100,000 revolutions per minute, the
bacterial flagellum is over 6 times more efficient than the fastest car. This wonder of nature
has sparked a wide range of interest in the science community in an effort to answer the
central question of origins.
What is a bacterial flagellum? Bacterial flagellum such as E. coli and S. typhimurium
found in bacteria rich places like uncooked meat or fecal matter; at first glance appear to be
designed with all parts (composed mainly of proteins) perfectly in place to function almost
like a motor. This “motor” contains many important parts to function such as a filament to
propel itself, a hook functioning like a joint, and the driver shaft which uses acid found
outside the cell to rotate the motor, like a dam. Its efficiency is astounding. It is actually
cited by some to be the most efficient motor or motor-like structure in the world, nearing
100 percent productivity.
How did this ingenious
motor-like structure come to be?
With all there is still to discover
and much variation between
flagella species, the answer at this
point, it still some what unclear.
While science cannot say exactly
how complex bacterial flagellums
evolved, the evidence seems to
point to similar functioning
bacteria with about 30 fewer
protein structures than a bacterial
flagellum called type III secretory
system, or TTSS. This seeming
precursor to the bacterial flagellum
is a disease-causing bacterium.
This drawing captures a few
important parts to a bacterial
flagellum.
It is not propelled by a motor-like structure but
instead contains something resembling a syringe
in the place of the flagellum which it uses to inject its disease.
Bacterial flagellums also have an advantage over other bacterium without flagellums
because their filament can rotate clockwise and counter-clockwise. This is beneficiary to
bacteria flagellum because not only can they move farther and faster than competitors, they
can also change direction on a whim. It’s thought that there rotary motor developed from the
mutation of an ion-powered pump used to get rid of waste. This flagella propeller continues
to aid in the survival in these bacteria and have become quite a favorable adaptation.
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