What does the cells cytoskeleton look like?
Microtubules (the cytosketon) are hollow tubes of variable
length and about 25nm diameter. They are stiff but flexible.
Microtubules are assembled in a line from building blocks of
tubulin molecules grouped into pairs called a dimer. Dimers are
joined end-to-end by the process of polymerization to form a linear
polymer called a protofilament. Thirteen protofilaments lying in
parallel are formed into a circular tube with the duct running down
the middle. This is a microtubule.
The cytoskeleton also enable cilia, flagella and sperm to move.
Throughout the life of the cell various molecules and cargo
containing vesicles are transported around the cell by motor
proteins by moving along the protein filaments using them as
highways.