A molecular motor couples an energy supply to directed mechanical motion. ATP synthase provides a rotary example.
In inchworm motion the same head remains in front as the two heads advance without exchanging order. Ideal fixed label positions then advance by one centre-of-mass step per cycle, contrasting with the unequal alternating displacements possible in hand-over-hand motion of a two-headed motor.
In hand-over-hand motion, two attached heads exchange their leading and trailing roles. For a centre-of-mass advance , one head can move about while the other remains fixed. The motion of a fluorescent label also depends on its position on the motor.[ref]
Myosin V Walks Hand-Over-Hand: Single Fluorophore Imaging with 1.5-nm Localization by Ahmet Yildiz and others. Alternating light-chain label displacements support head exchange
A microtubule-associated molecular motor family. Many transport cargos toward plus ends, although direction and function vary among family members.
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Molecular motors are specialized proteins that generate movement at the molecular level within cells. They convert chemical energy, typically derived from the hydrolysis of ATP (adenosine triphosphate), into mechanical work. Molecular motors play critical roles in various cellular processes, including muscle contraction, intracellular transport, and cell division.