Cytoskeleton: a network of protein fibers in the cytoplasm thatgives shape to a cell, holds and moves organelles, and is typically involved in cell movement.
Cytoskeleton of a cultured epithelial cell. Microtubules
are shown in green, actin is shown in red and DNA is in blue.
Image by Steve Rogers.
Audesirk, Teresa and Gerald, Biology,
Prentice Hall, 1999
The
cytoskeleton maintains the cell shape. When you think of
the cytoskeleton, think of pillars of a building.
Eukaryotic cells are
given shape and organized by the cytoskeleton, which consists
of three types of proteins: microtubules, intermediate filaments,
and microfilaments.
Microfilaments are twisted
double strands consisting of a string of proteins, from 7 nm to
several cm long. The protein is actin. Its function
helps muscle contraction, cell shape, and movement in cytoplasm.
Intermediate filamentsare
made of eight subunits in rope-strands. The proteins structure
varies with different tissue types. This component helps
maintain shape, support nerve cell extentions, and attach cells
together.
Microtubules are tubes
made up of spiraling, two-part subunits. It is made of tubulin.
It aids in chromosome movement, movement of organelles, and the
movement of cilia and flagella.
Without the cytoskeleton,
the cell would have no shape. By allowing the cell to keep
shape, the cell is allowed to function and stay in homeostasis.
Reference
Audesirk, Teresa and Gerald, Biology,
Prentice Hall, 1999