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TheNobelPrizeinPhysiologyorMedicine2009?http://nobelprize.org1(12)TheNobelPrizeinPhysiologyorMedicine2009isawardedtoElizabethH.Blackburn,CarolW.GreiderandJackW.Szostakforthediscoveryof“howchromosomesareprotectedbytelomeresandtheenzymetelomerase”Thisyear’sNobelPrizeisawardedtothreescientistswhohavesolvedoneofbiology’sgreatmysteries:Howarethechromosomesthatcarryourgenescopiedintheirentiretyduringcelldivisionandprotectedagainstbreakdown?TheNobelLaureateshaveshownthattheanswerliesinthechromosomes’ends–thetelomeres–andintheenzymethatformsthem–telomerase.ElizabethBlackburnandJackSzostakwerethefirsttoshowthattheuniqueDNAsequencecontainedinthetelomeresservestoprotectthechromosomes.CarolGreiderandElizabethBlackburnwerethenabletoshowhowthetelomerescouldbeextendedbytheenzymetelomerase.Thesediscoverieshavehelpedusunderstandhowourgenesandcellsaremaintainedthroughoutlife.Telomeresandtelomerasealsoplayanimportantroleinvariousdiseasessuchascancer.Thisknowledgehasalsogivenusgreaterinsightintohowourcellsandbodiesage.StickychromosomesInterestintelomereswasfirstkindledinthe1930swhentheresearchersBarbaraMcClintockandHermannMullernoticedthattheendsofchromosomeappearedtoplaysomeprotectiverole.BarbaraMcClintockobservedthatchromosomeslackingendpartsbecame“sticky”–theyoftenfusedtoeachotherorgotbrokendown.SimilarobservationswerereportedbyHermannMuller,whocoinedthetermtelomerefromtheGreektelos(end)andmeros(part).Atthattime,theinternalstructureofthechromosomewasessentiallyunknown.Researchersknewthatchromosomescarrythegeneticmaterial,andsuspectedthatthetelomeresprotectitfromdegradation,buttheycouldnotunderstandhow.TheNobelPrizeinPhysiologyorMedicine2009?http://nobelprize.org2(12)ThetelomereChromosomescontainthelongstrandsofDNAthatcompriseourgenes.Telomeresformcapsattheendsofthechromosomes.ManyprimitiveorganismssuchasbacteriahavecircularDNAmoleculeswhichhavenoendsthatneedtobecopied.Animalsandhumans,ontheotherhand,haveli
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