Microtubules ( + + ) are a component of the
cytoskeleton, found throughout the
cytoplasm. These tubular polymers of
tubulin can grow as long as 50
micrometres and are highly dynamic. The outer diameter of a microtubule is about 24
nm while the inner diameter is about 12 nm. They are found in
eukaryotic cells, as well as some
Bacteria, and are formed by the polymerization of a
dimer of two globular
proteins, alpha and beta
tubulin.