RNA(biochemistry)alonglinearpolymerofnucleotidesfoundinthenucleusbutmainlyinthecytoplasmofacellwhereitisassociatedwithmicrosomes;ittransmitsgeneticinformationfromDNAtothecytoplasmandcontrolscertainchemicalprocessesintRNAmolecule(physicsandchemistry)thesimpleststructuralunitofanelementorcompoundmoleculethatcancatalyzeachemicalreaction(chemistry)aprocessinwhichoneormoresubstancesarechangedintootherschemicalreaction.Manynaturalribozymescatalyzeeithertheirowncleavage(embryology)therepeateddivisionofafertilisedovumcleavageorthecleavageofotherRNAs,buttheyhavealsobeenfoundtocatalyzetheaminotransferaseactivityoftheribosomeAnorganelleinthecytoplasmofalivingcell;ribosomesattachtomRNAandmovedownitonecodonatatimeandstopuntiltRNAbringstherequiredaminoacid;whenaribosomereachesastopcodonitfallsapartandreleasesthecompletedproteinmolecuribosome.Investigatorsstudyingtheoriginoflifeoriginoflifehaveproducedribozymesinthelaboratorythatarecapableofcatalyzingtheirownsynthesiscatalyzingtheirownsynthesisunderveryspecificconditions.Beforethediscoveryofribozymes,onlyproteinsAnyofalargegroupofnitrogenousorganiccompoundsthatareessentialconstituentsoflivingcells;consistofpolymersofaminoacids;essentialinthedietofanimalsforgrowthandforrepairoftissues;canbeobtainedfrommeatandeggsandmilkaproteinswereknowntohavecatalyticcatalyticactivity.In1967,CarlWoeseCarlWoese,FrancisCrickEnglishbiochemistwho(withWatsonin1953)helpeddiscoverthehelicalstructureofDNA(bornin1916)FrancisCrick,andLeslieOrgelLeslieOrgelwerethefirsttosuggestthatRNAcouldactasacatalystbaseduponfindingsthatitcanformcomplexsecondarystructuresecondarystructures.Thefirstribozymewasdiscoveredinthe1980sbyThomasR.Cech,whowasstudyingRNAsplicing(genetics)splicing(genetics)intheciliatedprotozoanTetrahymenathermophila.ThisribozymewasfoundintheintronSequenceofaeukaryoticgene'sDNAthatisnottranslatedintoaproteinintronofanRNAtranscriptandremoveditselffromthetranscript.RibozymesoftenhavedivalentmetalionssuchasMg2+ascofactorAsubstance(asacoenzyme)thatmustjoinwithanothertoproduceagivenresultcofactorsAlthoughribozymesarequiterareinthecell,theirrolesaresometimesessentialtolifeTheperiodduringwhichsomethingisfunctional(asbetweenbirthanddeath)life.Forexample,thefunctionalpartoftheribosomeAnorganelleinthecytoplasmofalivingcell;ribosomesattachtomRNAandmovedownitonecodonatatimeandstopuntiltRNAbringstherequiredaminoacid;whenaribosomereachesastopcodonitfallsapartandreleasesthecompletedproteinmolecuribosome,themolecularmachinethattranslatesRNAintoproteins,isfundamentallyaribozyme.
