Flagellum

From CreationWiki, the encyclopedia of creation science

Escherichia coli cells use long, thin structures called flagella to propel themselves. These flagella form bundles that rotate counter-clockwise, creating a torque that causes the bacterium to rotate clockwise.

The flagellum is a molecular motor (nanomachine) used by microscopic organisms, such as bacteria and protozoans, to propel themselves through an aqueous medium. The bacterial flagellum is a helical filament that rotates like an outboard motor, while the eukaryote flagellum is a whip-like structure that lashes back and forth.

Bacterial flagellum

The bacterial flagellum is composed of about 25 different proteins, each of them in multiple copies ranging from a few to tens of thousands. It is driven by a rotary motor with a diameter of only 30 to 40 nm. Much like the modern rotary engine, the bacterial flagellum consists of many different parts that carry out different functions, such as a rotary motor, bushing, drive shaft, rotation-switch regulator, universal joint, helical propeller, and rotary promoter for self-assembly.^[1] The filament of the bacterial flagellum is a hollow tube composed of protein, and is only 20 nanometers thick. It is helical, and has a sharp bend just outside the outer membrane called the "hook" which allows the helix to point directly away from the cell. A shaft runs between the hook and the basal structure, passing through protein rings in the cell's membranes that act as bearings.^{[Reference needed]}

The engine can operate at 6,000 to 17,000 rpm, but with a filament attached usually only reaches 200 to 1000 rpm.^{[Reference needed]}. The motor drives the rotation of the flagellum at around 300 Hz, at a power level of 10^-16 W with energy conversion efficiency close to 100 %.^[1]

Intelligent design

Main Article: Intelligent design

The flagellum is a classic example of the kinds of intelligent design that can be found in even the simplest of organisms. ID advocates, such as Michael Behe have helped elucidate the flagellum as irrefutable proof of ID by illustrating the irreducibly complex function of its systems.

Modern physicists look to molecular motors, like the bacterial flagellum, in an attempt to clean methods of designing modern engines in the hope of reaching the functional efficiency evident within the creation.

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According the American Institute of Physics: The structural designs and functional mechanisms to be revealed in the complex machinery of the bacterial flagellum could provide many novel technologies that would become a basis for future nanotechnology, from which we should be able to find many useful applications..^[1]

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Flagellum Assembly

Gallery

Electron micrograph of H. pylori possessing multiple flagella.	A bacterium with a whip-like flagellum.	Electron micrograph of a sperm with flagellum penetrating an ovum.	Diagram of choanocyte. The flagella create water currents that bring nutrients into the interior of a sponge.
Examples of bacterial flagaella arrangment schemes. A-Monotrichous; B-Lophotrichous; C-Amphitrichous; D-Peritrichous.