Microtubules are the largest type of filament, with a diameter of about 25 nanometers (nm), and they are composed of a protein called tubulin. Actin filaments are the smallest type, with a ...

Microtubules are composed of a protein called tubulin, which consists of alpha and beta subunits that assemble into large, tube-shaped filaments within the cell. These fibers are dynamic, growing from ...