▁catal yt ic ▁properties ▁of ▁R NA ." ▁The ▁term ▁rib oz yme ▁was ▁first ▁introduced ▁by ▁Kelly ▁Kru ger ▁et ▁al . ▁in ▁ 1 9 8 2 ▁in ▁a ▁paper ▁published ▁in ▁Cell . ▁ ▁It ▁had ▁been ▁a ▁firm ly ▁established ▁belief ▁in ▁bi ology ▁that ▁catal ysis ▁was ▁reserved ▁for ▁prote ins . ▁However , ▁the ▁idea ▁of ▁R NA ▁catal ysis ▁is ▁motiv ated ▁in ▁part ▁by ▁the ▁old ▁question ▁regarding ▁the ▁origin ▁of ▁life : ▁Which ▁comes ▁first , ▁en zym es ▁that ▁do ▁the ▁work ▁of ▁the ▁cell ▁or ▁nucle ic ▁ac ids ▁that ▁carry ▁the ▁information ▁required ▁to ▁produce ▁the ▁en zym es ? ▁The ▁concept ▁of ▁" rib on uc le ic ▁ac ids ▁as ▁catal yst s " ▁circum vent s ▁this ▁problem . ▁R NA , ▁in ▁ess ence , ▁can ▁be ▁both ▁the ▁ch icken ▁and ▁the ▁egg . ▁ ▁In ▁the ▁ 1 9 8 0 s ▁Thomas ▁C ech , ▁at ▁the ▁University ▁of ▁Colorado ▁at ▁B ould er , ▁was ▁studying ▁the ▁exc ision ▁of ▁intr ons ▁in ▁a ▁rib os om al ▁R NA ▁gene ▁in ▁T et rah ym ena ▁therm oph ila . ▁While ▁trying ▁to ▁pur ify ▁the ▁en zym e ▁responsible ▁for ▁the ▁sp lic ing ▁reaction , ▁he ▁found ▁that ▁the ▁intr on ▁could ▁be ▁sp lic ed ▁out ▁in ▁the ▁absence ▁of ▁any ▁added ▁cell ▁extract . ▁As ▁much ▁as ▁they ▁tried , ▁C ech ▁and ▁his ▁colle agues ▁could ▁not