What is the role of a ribosome?
Ribosomes are the sites of protein synthesis, where RNA is translated into protein. When cells need large numbers of proteins, they must first build numerous ribosomes. Because protein synthesis is so important to cells, there are large numbers of ribosomes found throughout cells often numbering in the hundreds or thousands. In eukaryotic cells, three of the four ribosomal RNA strands are synthesized in the nucleolus, a structure in the nucleus. The fourth ribosomal RNA strand is synthesized outside of the nucleolus and then transported into the nucleolus for ribosome assembly. Ribosomal proteins enter the nucleolus and combine with the four ribosomal RNA strands to create the large and small subunits which are two ribosomal structures. The two subunits unite outside the nucleus just before the ribosome begins to manufacture proteins. Prokaryotic cells lack a nucleus or nucleolus and therefor ribosomal synthesis takes place in the cytoplasms. Without the ribosomes the message would not
