ABSTRACT
Eukaryotic cells have an internal scaffold, the cytoskeleton, that controls the shape and movement of the cell and the organelles within it. The cytoskeleton consists of microfilaments, intermediate filaments and microtubules. In the cytosol of eukaryotic cells is an internal scaffold, the cytoskeleton. The microfilaments, diameter 5—9 nm, have a mechanically supportive function, determining the shape of the cell's surface and they are involved in whole cell movement. The third type of cytoskeletal filaments, the microtubules, determines the position of membrane-bound organelles and directs their intracellular transport. Molecular motors or motor proteins bind to cytoskeletal filaments and use energy derived from the hydrolysis of adenosine triphosphate (ATP) to move along them. The head region or motor domain which hydrolyses ATP binds to the filament, while the tail region binds the cargo. The major types of motor proteins are the myosins, the kinesins and the dyneins.
