The
cytoskeletonhelps to determine cell shape,
internal organization, and movement. The cytoskeleton is an
interconnected system of fibers, threads, and lattices that
extends between the nucleus and the plasma membrane. It
gives cells their internal organization, overall shape, and capacity
to move. The main components are
microtubules,microfilaments, and intermediate filaments.
These are assembled from protein subunits. Some portions are
transient, such as the "spindle" microtubules used in
chromosome movement during cell division; others are
permanent, such as filaments operational in muscle
contraction.
Through the controlled assembly and disassembly of their
subunits, microtubules and microfilaments grow or shrink in
length (example: movement of chromosomes). Microfilaments or
microtubules actively slide past one another (example: muscle
movement). Microtubules or microfilaments shunt organelles
from one location to another (example: cytoplasmic
streaming).
This animation (Audio - Important) describes the
cytoskeleton.
REVIEW: Which type of cytoskeletal protein is responsible for the movement of chromosomes during
cell division?
