The cytoskeleton of eukaryotic cells is made of filamentous proteins and provides mechanical support to the cell and its parts.
All cytoskeletons consist of three major classes of elements that differ in size and in protein composition. Microtubules are
the largest type of filament, with a diameter of about 25 nm and they are composed of a protein called tubulin while Actin
filaments are the smallest type with a diameter of about 6 nm and Intermediate filaments are mid-sized, with a diameter of
about 10 nm. Microtubules radiate out from the centrosome to provide the basic organization of the cytoplasm, including the
positioning of cellular organelles.
Microtubules have several other important functions. AL BUT ONE is a function of cellular microtubules.
Function in intracellular transport
Aid in cell division and chromosome movement
Aid in assembling amino acids during protein synthesis.
Function in movement as they compose the cilia and flagella of animal
cells.

Microtubules are the structures that help in the support of the cell and the cellular organelles. These microtubules are formed of the actin myosin and tubulin proteins. These proteins help to keep the cellular organelles in position.

These microtubules also help in the particular placements and transportation of the substances that are needed to be transported from one part of cell to other.

The microtubules also help in the cytokinesis and the mitosis and meiosis of the cells. The spindle fibres also are one of the types of microtubules of cells.

But microtubules are not associated with the amino acid transportation. That is aided by golgi bodies and endoplasmic reticulum.