What are microtubules composed of?

Microtubules are primarily composed of tubulin protein, which consists of two subunits: alpha-tubulin and beta-tubulin. These subunits work together to form a hollow cylindrical structure, which is crucial for various cellular functions. Microtubules play a vital role in maintaining the cell's shape, facilitating intracellular transport, and organizing the mitotic spindle during cell division. Their dynamic nature allows them to grow and shrink as necessary, enabling the cell to adapt to different processes, such as motility and the movement of organelles. The unique structure and composition of microtubules are fundamental to their function in the cytoskeleton and overall cellular activities.