Microtubules

Definition

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

5 Must Know Facts For Your Next Test

1. Microtubules are dynamic polymers that can rapidly grow and shrink by adding or losing tubulin subunits.
2. They originate from microtubule-organizing centers (MTOCs), such as centrosomes in animal cells.
3. Microtubules are essential for the separation of chromosomes during mitosis and meiosis.
4. Motor proteins like kinesin and dynein move along microtubules to transport cellular cargo.
5. The stability of microtubules is regulated by various associated proteins, including MAPs (Microtubule-Associated Proteins).

Review Questions

• What are the primary functions of microtubules within a cell?
• How do motor proteins interact with microtubules to facilitate intracellular transport?
• Where do microtubules typically originate within an animal cell?

Related terms

Cytoskeleton:

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

Centrosome: An organelle that serves as the main microtubule-organizing center (MTOC) in animal cells and plays a key role during cell division.

Tubulin: A globular protein that polymerizes to form microtubules; it exists primarily as alpha-tubulin and beta-tubulin dimers.