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Before the discovery of ribozymes, only proteins were known to have catalytic activity. In 1967, Carl Woese, Francis Crick, and Leslie Orgel were the first to suggest that RNA could act as a catalyst based upon findings that it can form complex secondary structures. The first ribozyme was discovered in the 1980s by Thomas R. Cech , who was studying RNA splicing (genetics)In genetics, splicing is a modification of genetic information prior to translation. In eukaryotes, a gene often contains altering sequences known as exons and introns. In contrast to prokaryotes, which do not have introns, the primary mRNA transcript cal in the ciliated protozoan Tetrahymena thermophila . This ribozyme was found in the intronIntrons are sections of DNA within a gene that do not encode part of the protein that the gene produces, and are spliced out of the mRNA that is transcribed from the gene before it is exported from the cell nucleus. Introns exist mainly (but not only) in of an RNA transcript and removed itself from the transcript. Ribozymes often have divalent metal ions such as Mg²⁺ as cofactorA cofactor is any substance that needs to be present in addition to an enzyme to catalyse a certain reaction. However, more or less ubiquitous substances such as water do not qualify. Some cofactors are inorganic, such as the metal atoms zinc, iron, and cs

Although ribozymes are quite rare in the cell, their roles are sometimes essential to lifeAlternate uses: see Life (disambiguation) and Living (disambiguation Life is a multi-faceted concept with no simple definition; this article is confined to the primary meanings in biology; articles on life in other senses are included in the article life. For example, the functional part of the ribosome, the molecular machine that translates RNA into proteins, is fundamentally a ribozyme.

RNA can also act as a hereditary molecule, which encouraged Walter GilbertWalter Gilbert (born March 21, 1932) is an American physicist, biochemist, entrepreneur, and molecular biology pioneer. He was awarded the 1980 Nobel Prize in Chemistry with Paul Berg and Frederick Sanger. Gilbert and Sanger were recognized for their pion to propose that in the past, the cell used RNA as both the genetic material and the structural and catalytic molecule , rather than dividing these functions between DNA and protein as they are today. This hypothesis became known as the " RNA world hypothesis" of the origin of life.

If ribozymes were the first molecular machines used by early life, then today's remaining ribozymes -- such as the ribosome machinery -- could be considered living fossils of a life based primarily on nucleic acids.

A recent test-tube study of prion folding suggests that an RNA may catalyze the pathological protein conformation in the manner of a chaperone enzyme.

Some known ribozymes include RNase P, Group I and Group II introns, leadzyme , hairpin ribozyme , hammerhead ribozyme , hepatitis delta virus ribozyme , tetrahymena ribozyme