Microtubule structure
Microtubule is composed of globular subunits. They polymerize to form the microtubule which functions like a rod on which march the motor proteins moving around their load like chromosome or indirectly also another microtubule so that the poles of the spindle are pushed apart.
Scroll down to see the virtual reality world!
VRML Virtual reality world. If you do not see it below, pleasedownload the free plugin.