片断:Chapter1IntroductiontoBioorganicChemistry"llmightbehelpful10rrminiliwrselvesrcglariyofthesizcttbleincompletenessofourunderstanding.notonlyofourselves(tsindividualsandusilgroup,hutalsoofNatureandtheworldaroundus.N.Hai-kermanScience183.907(1974)1.1BasicConsiderationsAmongthefirstpersonstodevelopbioorientedorganicprojectswasF.H.Westheimer.inthe1950s.Hewasprobabiythefirstphysicalorganicchemisttodoseriousstudiesot'biochemicalreactions.However.itwasonlytwentyvearslaterthatthefieldblossumedtowhatisnowacceptedasbioorganicchemistry.Bioorganicchemistrvisadisciplinethatisessentialtyconcernedwiththeapplicationofthetoolsot'chemistrytotheunderstandingolbio-chemicalprocesses.Suchanunderstandingisot'tenachievedwiththeaidot'moleculurmodelschemicallysynthesizedinthelaboratory.Thisallowsa"sortingout"ofthemanyvariableparameterssimultaneouslyoperativewithinthebiologicalsystem.Forexample.howdoesabiologicatmembranework?Onebuildsasimplemodelofknowncompositionsandstudiesasinglebehavior,suchasaniontransportproperty.Howdoesthebrainwork?Thisisbyfarz,morecomplicatedsystemthanthepreviouscxample.Againonestudiessinglesynapsesandsinglesynaptieconstituentsandthenasestheobservationstoconstructamodel.Organicchemistsdevelopsyntheticmethodologytobetterunderstandorganicmechanismsandcreatenewcompounds.Ontheotherhand,biochemistsstudylifeprocessesbymeansofbiochemicalmethodology:enzymepurificationandassay,radioisotopictracerstudiesininvivosystems.Theformerpossessthemethodologytosynthesizebiologicalanalogsbutoftenfailtoappreciatewhichsynthesiswouldberelevant.Thelatterpossessanappreciationofwhatwouldbeusefultosynthesizeinthelaboratorybutnottheexpertisetopursuetheproblem.Theneedforthemultidisciplinaryapproachbecomesobvious,andthebioorganicchemistwilloftenhavetwolaboratories:oneforsynthesisandanotherforbiologicalstudy.Anewdimensionresultsfromthiscombinationofchemicalandbiologicalsciences,thatis,theconceptofmodelbuildingtostudyandsortoutthevariousparametersofacomplexbiologicalprocess.Bymeansofsimpleorganicmodels,manybiologicalreactionsaswellasthespecificityandefficiencyoftheenzymesinvolvedhavebeenrepro-ducedinthetesttube.Thesuccessofmanyofthesemodelsindicatestheprogressthathasbeenmadeinunderstandingthechemistryoperativeinbiologicalsystems.Extrapolationofthismultidisciplmarysciencetothepathologicalstateisamajorthemeofthepharmaceuticalindustry-organicchemistsandpharmacologistsworking"sidebyside,"sothatbioorganicchemistryistobiochemistryandmedicinalchemistryistopharmacology.Whatarethetoolsneededforbioorganicmodelstudies?Organicandphysicalorganicchemicalprincipleswillprovide.bytheirverynature,thebestopportunitiesformodelbuilding-modelingmoleculareventsthatformthebasisoflife.Alargeportionoforganicchemistryhasbeenclassicallydevotedtonaturalproducts.Manyofthoseresultshaveturnedouttobewonderfultoolsforthediscoveryandcharacterizationofspecificmoleculareventsinlivingsystems.Think,forinstance,ofthedevelop-mentofantibiotics,certainalkaloids,andthedesignofnewdrugsforthemedicineot'todayandtomorrow.Alllivingprocessesrequireenergy,whichisobtainedbyperformingchemicalreactionsinsidecells.Thesebiochemicalprocessesarebasedonchemicaldynamicsandinvolvereductionsandoxidations.Biologicaloxidationsarethusthemainsourceofenergytodriveanumberofendergonicbiologicaltransformations.Manyofthereactionsinvolvecombustionoffoodssuchassugarsandlipidstoproduceenergythatisusedforavarietyofessentialfunctionssuchasgrowth,replication,maintenance,muscularwork.andheatpro-duction.Thesetransformationsarealsorelatedtooxygenuptake;breathingisabiochemicalprocessbywhichmolecularoxygenisreducedtowater.Throughoutthesepathways,energyisstoredintheformofadenosnetriphosphate(ATP),anenergy-richcompoundknownastheuniversalproductofenergetictransactions.