Microtubules are hollow tubes that are composed of tubulin proteins and help the cell transport materials within itself and resist shape changes.
Microtubules are the largest element (~25 nm diameter) of the cytoskeleton and commonly used by eukaryotic cells. The walls of the microtubule are made of polymerized dimers of α-tubulin and β-tubulin, two globular proteins. They help the cell resist compression, provide a track along which vesicles move through the cell, and pull replicated chromosomes to opposite ends of a dividing cell. Like microfilaments, microtubules can dissolve and reform quickly.
MCAT Official Prep (AAMC)
Biology Question Pack, Vol 2. Question 99
• Microtubules play roles in cell structure maintenance, material transport, whole cell movement, and cell division.
Cytoskeleton: network of protein fibers that help with cellular movement and maintaining its structure/shape
Flagellum: a lash-like appendage that protrudes from the cell body of certain prokaryotic and eukaryotic cells that help move the entire cell
Cilia: short, hair-like structures that are used to move entire cells or substances along the outer surface of the cell
Microtubule: small tubes made of protein that help cells move material around itself and resist compression
Tubulin: globular proteins that make up microtubules.