key term - Microtubules

Definition

Microtubules are cylindrical structures composed of tubulin proteins that form part of the cytoskeleton in eukaryotic cells. They play critical roles in maintaining cell shape, enabling intracellular transport, and facilitating cell division.

5 Must Know Facts For Your Next Test

1. Microtubules are composed of alpha and beta tubulin dimers.
2. They are essential for the formation of the mitotic spindle during cell division.
3. Microtubules provide tracks for motor proteins like kinesin and dynein to transport cellular cargo.
4. They originate from microtubule organizing centers (MTOCs) such as centrosomes in animal cells.
5. Cilia and flagella, which enable movement in some unicellular eukaryotic parasites, are made up of microtubules.

Review Questions

Related terms

Cytoskeleton:

A network of protein fibers in the cytoplasm that provides structural support and facilitates cell movement.

Kinesin: A motor protein that moves along microtubules carrying cellular cargo toward the plus end.

Centrosome: An organelle that serves as a main microtubule organizing center and is crucial for the formation of mitotic spindles during cell division.