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Structural components within the basal body of the flagellum allow the inner portion of this structure, the rods of the basal body, and the attached hook–
filament complex to rotate. The outer rings remain statically in contact with the inner and outer cell membranes and cell wall (murein), anchoring the
flagellum complex to the bacterial cell envelope. Rotation is driven by the flow of protons through the motor from the periplasmic space, outside the cell
membrane, into the cytoplasm in response to the electric field and proton gradient across the membrane, which together constitute the proton motive
force. A switch determines the direction of rotation, which in turn determines whether the bacteria swim forward (by counterclockwise rotation of the
flagellum) or tumble (caused by clockwise rotation of the flagellum). (Reproduced with permission from Saier MH Jr: Peter Mitchell and his chemiosmotic
Source: Cell Structure, Jawetz, Melnick, & Adelberg’s Medical Microbiology, 27e
theories. ASM News 1997;63:13.)
Citation: Carroll KC, Hobden JA, Miller S, Morse SA, Mietzner TA, Detrick B, Mitchell TG, McKerrow JH, Sakanari JA. Jawetz, Melnick, &
Adelberg’s Medical Microbiology, 27e; 2015 Available at: http://mhmedical.com/ Accessed: May 07, 2017
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