cytoplasm
Ribosomes are produced in the nucleolus, and then transported to the cytoplasm. Ribosomes are made of ribosomal proteins, called ribonucleoproteins , and ribosomal RNA rRNA . Each ribosome has two parts, a large and a small subunit, as shown in Figure below . The subunits are attached to each other. During translation, the smaller subunit binds to the mRNA, while the larger subunit binds to the tRNA with attached amino acids. When a ribosome finishes reading an mRNA molecule, the two ribosomal subunits disassociate.