17. Functions: They provide the tracks along with several different molecular motors for transport vesicles, organelles such as secretory granules, and mitochondria from one part of the cell to another. They also form the spindle, which moves the chromosomes in mitosis. Microtubules can transport in both directions. Applied Physiology: Microtubule assembly is prevented by colchicine and vinblastine. The anticancer drug paclitaxel (Taxol) binds to microtubules and makes them so stable that organelles cannot move. Mitotic spindles cannot form, and the cells die .
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22. In mammals, they are generally sausage-shaped , has an outer membrane , an intermembrane space , an inner membrane , which is folded to form shelves (cristae), and a central matrix space . The enzyme complexes responsible for oxidative phosphorylation are lined up on the cristae , synthesize a “high-energy” substance called adenosine triphosphate (ATP)