Cytoskeleton
Say it: SY-toh-skel-uh-tun
The cytoskeleton is a network of protein filaments inside a cell that gives it shape, holds organelles in place and powers movement and division.
Definition
What is the cytoskeleton?
The cytoskeleton is a web of protein fibers that runs through the cytoplasm of eukaryotic cells. Unlike a bony skeleton, it is constantly being built up and taken apart, so a cell can change shape, crawl, divide and move its contents around. Bacteria have simpler relatives of the same proteins.
It has three main kinds of fiber, told apart by width. Microfilaments, the thinnest, are twisted chains of the protein actin; working with the motor protein myosin, they drive muscle contraction, the crawling of white blood cells and the pinching in two of a dividing animal cell. Intermediate filaments, of middle width, are rope-like fibers such as keratin in skin and hair; they are purely structural, bearing tension and anchoring the nucleus. Microtubules, the widest, are hollow tubes of tubulin that resist compression, serve as tracks along which motor proteins haul vesicles, form the spindle that separates chromosomes, and make up the core of cilia and flagella.
Many medical problems trace back to the cytoskeleton. Faulty intermediate-filament proteins cause some inherited skin and muscle diseases, defective cilia can lead to chronic chest infections and infertility, and several cancer drugs work by jamming the microtubules of dividing cells.
Word parts
Where does the word “cytoskeleton” come from?
- cyto-
- hollow vessel; now cellGreek kytos
- skeleton
- dried up (a dried body)Greek skeletos
Practice it
Where you'll meet it
Related
Terms that go with it
- MicrotubuleA microtubule is a hollow tube built from the protein tubulin, one of the main cytoskeleton fibers, used for cell shape, transport and cell division.
- FlagellumA flagellum is a long, whip-like projection that some cells, including many bacteria and sperm, use to swim through liquid.
- CytokinesisCytokinesis is the last stage of cell division, in which the cytoplasm of one cell is split to form two separate daughter cells.
- CytoplasmThe cytoplasm is everything inside a cell's plasma membrane apart from the nucleus: the jelly-like cytosol and the structures suspended in it.
- OrganelleAn organelle is a specialized structure inside a cell, usually wrapped in its own membrane, that carries out a particular job for the cell.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- OpenStax Biology 2e, 4.5 The Cytoskeleton
- MedlinePlus Genetics: What is a cell?
- NCI Dictionary of Cancer Terms: cytoskeleton
- NCBI MeSH: Cytoskeleton
Last updated
Spotted a mistake? Tell us and we'll correct it.
Practice Cell Biology
Free cell biology quizzes, with an explanation for every answer.
See the Quizzes