1生命源于细胞1.1细胞共性与多样性1.2细胞内分子1.3细胞的作用1.4基因的进化Asingle~200micrometer(µm)cell,thehumanegg,withsperm,whicharealsosinglecells.Fromtheunionofaneggandspermwillarisethe10trillioncellsofahumanbody.[PhotoResearchers,Inc.]1.1细胞的共性和多样性不同生物的尺寸Prokaryoticcellshaveasimplerinternalorganizationthaneukaryoticcells1.2细胞内分子•SmallMoleculesCarryEnergy(ATP),TransmitSignals(hormone),andAreLinkedintoMacromolecules(polysaccharides)•ProteinsGiveCellsStructureandPerformMostCellularTasks•NucleicAcidsCarryCodedInformationforMakingProteinsattheRightTimeandPlaceNucleicAcidsCarryCodedInformationforMakingProteinsattheRightTimeandPlace•DNAconsistsoftwocomplementarystrandswoundaroundeachothertoformadoublehelix.1.3细胞的作用•胞内分子的生产和调节•细胞感应和传递信息•细胞调节基因表达•细胞的生长和分裂•细胞死亡细胞感应和传递信息细胞的生长和分裂细胞死亡•破坏性损伤•细胞自然凋亡1.4基因的进化•人类和其他动物控制发育的很多基因是非常相似的•达尔文有关生物进化的观点都与基因有关•人类许多药物的研究得益于对其它生物的研究类似基因•DevelopmentofthelargecompoundeyesinfruitfliesrequiresagenecalledeyelessFlieswithinactivatedeyelessgeneslackeyes.•Normalhumaneyesrequirethehumangene,calledPax6,thatcorrespondstoeyeless.•PeoplelackingadequatePax6functionhavethegeneticdiseaseaniridia(无虹膜)人类许多药物的研究得益于对其它生物的研究谢谢