Microtubules are the largest cytoskeletal elements, with a diameter of about 25 nm. They are composed of tubulin dimers, which polymerize to form hollow tubes. Microtubules are essential for maintaining cell shape, facilitating intracellular transport, and segregating chromosomes during cell division. They are organized by the centrosome in animal cells, which serves as the main microtubule-organizing center (MTOC). Microtubules also form the core structure of cilia and flagella, enabling their motility.
