Microtubules are cylindrical structures made of protein subunits called tubulin. They are a key component of the cytoskeleton in eukaryotic cells, providing structural support and shape. Microtubules play essential roles in various cellular processes, including cell division, intracellular transport, and maintaining cell integrity. These structures are dynamic, meaning they can grow and shrink as needed, allowing cells to adapt to different conditions. Microtubules also form the basis of structures like cilia and flagella, which are important for cell movement. Additionally, they are involved in the organization of organelles within the cell, contributing to overall cellular function.