Until the 1980s, researchers believed all enzymes consisted of protein. However, a molecule known as ribonucleic acid, or RNA, can also function as an enzyme. RNA is involved in protein synthesis within your cells, and, during the process, it can catalyze a reaction on itself or on another RNA molecule to splice unneeded material from the molecule and rejoin the cut ends. When RNA functions in this capacity, it is known as a ribozyme. Since the discovery of the first ribozyme, biochemists have found many more of these cut-and-paste enzymes within cells.