Lesson1vocabularysubcellularbacteriayeastfungialgaemammaliancellgeneticsmolecularbiologybiomassenzymeantibioticsteroidglucosevaccineInterferonfermentationMostofthepropertiesweassociatewithlifearepropertiesofthecytoplasm.Muchofthemassofacellconsistsofthissemifluidsubstance,whichisboundedontheoutsidebytheplasmamembrane.生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。Organellesaresuspendedwithinit,supportedbythefilamentousnetworkofthecytoskeleton.Dissolvedinthecytoplasmicfluidarenutrients,ions,solubleproteins,andothermaterialsneededforcellfunctioning.细胞器悬浮在其中，并由丝状的细胞骨架支撑。细胞质中溶解了大量的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。TheNucleus:InformationCentral（细胞核：信息中心）Theeukaryoticcellnucleusisthelargestorganelleandhousesthegeneticmaterial(DNA)onchromosomes.(Inprokaryotesthehereditarymaterialisfoundinthenucleoid.)真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质存在于拟核中）。Thenucleusalsocontainsoneortwoorganelles-thenucleoli-thatplayaroleincelldivision.Apore-perforatedsaccalledthenuclearenvelopeseparatesthenucleusanditscontentsfromthecytoplasm.细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔.Smallmoleculescanpassthroughthenuclearenvelope,butlargermoleculessuchasmRNAandribosomesmustenterandexitviathepores.小分子可以自由通过核膜，而象mRNA和核糖体等大分子必须通过核孔运输。Organelles:SpecializedWorkUnits（细胞器：特殊的功能单位）Alleukaryoticcellscontainmostofthevariouskindsoforganelles,andeachorganelleperformsaspecializedfunctioninthecell.Organellesdescribedinthissectionincluderibosomes,theendoplasmicreticulum,theGolgicomplex,vacuoles,lysosomes,mitochondria,andtheplastidsofplantcells.所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体，内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。Thenumberofribosomeswithinacellmayrangefromafewhundredtomanythousands.Thisquantityreflectsthefactthat,...
