Centrosome Definition Centrosomes are organelles that serve as the main microtubule-organizing centers for animal cells. Centrosomes are made up of two, barrel-shaped clusters of microtubules called “centrioles” and a complex of proteins that help additional microtubules to form. This complex is also known as the microtubule-organizing center (MTOC), since it helps organize the spindle fibers … Continue reading Centrosome