What function of free ribosomes?

Ribosomes are organelles within cells and are either bound or free. Organelles are structures inside the cells which perform specific functions. Bound ribosomes are attached to the organelle called the rough endoplasmic reticulum (rough because of the presence of the ribosomes) and there is also the smooth endoplasmic reticulum, without attached ribosomes. Ribosomes are protein producing "factories" and are abundant in cells actively involved in protein synthesis.

Free ribosomes are scattered throughout the cell and the protein they produce is for usage within the cell. Much of the protein produced by the bound ribosomes is transported for use outside the cell.