Deoxyribozymes, also called DNA enzymes, DNAzymes, or catalytic DNA, are DNA oligonucleotides that are capable of catalyzing specific chemical reactions, similar to the action of other biological enzymes, such as proteins or ribozymes (enzymes composed of RNA).However, in contrast to the abundance of protein enzymes in biological systems and the discovery of biological ribozymes in the 1980s,there are no known naturally occurring deoxyribozymes.Deoxyribozymes should not be confused with DNA aptamers which are oligonucleotides that selectively bind a target ligand, but do not catalyze a subsequent chemical reaction.With the exception of ribozymes, nucleic acid molecules within cells primarily serve as storage of genetic information due to its ability to form complementary base pairs, which allows for high-fidelity copying and transfer of genetic information.