Microtubule
Microtubules are a component of the cytoskeleton. These cylindrical polymers of tubulin can grow as long as 25 micrometers and are highly dynamic. The outer diameter of microtubule is about 25 nm. Microtubules are important for maintaining cell structure, providing platforms for intracellular transport, forming the mitotic spindle, as well as other cellular processes. There are many proteins that bind to microtubules, including motor proteins such as kinesin and dynein, severing proteins like katanin, and other proteins important for regulating microtubule dynamics.
Read more about Microtubule: Structure, Organization Within Cells, Nucleation and Growth, Dynamic Instability, Motor Proteins, Intracellular Viral Transport, Postulated Role in Consciousness, Additional Images