蔣悟生《生物專業(yè)英語(yǔ)》教學(xué)案

蔣悟生《生物專業(yè)英語(yǔ)》教/學(xué)案

LessonOne（4學(xué)時(shí)）InsidetheLivingCell:StructureandFunctionofInternalCellParts

LessonOne（4學(xué)時(shí)）

InsidetheLivingCell:StructureandFunctionofInternalCellParts

教學(xué)目的：使學(xué)生掌握細(xì)胞的組成結(jié)構(gòu)（各種細(xì)胞器以及它們?cè)诩?xì)胞中的位置），以及結(jié)構(gòu)與功能之間的關(guān)

系。各細(xì)胞器及功能相關(guān)英語(yǔ)詞匯以及主要用法。

教學(xué)重點(diǎn)：各細(xì)胞器的概念和功能，及相關(guān)英語(yǔ)詞匯的掌握

教學(xué)難點(diǎn)：專業(yè)英語(yǔ)詞匯的記憶

講授方法：以學(xué)生翻譯為主，老師講解相關(guān)專業(yè)知識(shí)輔助學(xué)生理解

授課時(shí)間：3月22日；3月29日

教學(xué)內(nèi)容：

Cytoplasm:TheDynamic,MobileFactory

細(xì)胞質(zhì)：動(dòng)力工廠

Mostofthepropertiesweassociatewithlifearepropertiesofthecytoplasm.Muchofthemassofacellconsists

ofthissemifluidsubstance,whichisboundedontheoutsidebytheplasmamembrane.Organellesaresuspended

withinit,supportedbythefilamentousnetworkofthecytoskeleton.Dissolvedinthecytoplasmicfluidare

nutrients,ions,solubleproteins,andothermaterialsneededforcellfunctioning.

生命的大部分特征表現(xiàn)在細(xì)胞質(zhì)的特征上。細(xì)胞質(zhì)大部分由半流體物質(zhì)組成，并由細(xì)胞膜（原生質(zhì)膜）包

被。細(xì)胞器懸浮在其中，并由絲狀的細(xì)胞骨架支撐。細(xì)胞質(zhì)中溶解了大量的營(yíng)養(yǎng)物質(zhì)，離子，可溶蛋白以

及維持細(xì)胞生理需求的其它物質(zhì)。

TheNucleus:InformationCentral（細(xì)胞核：信息中心）

Theeukaryoticcellnucleusisthelargestorganelleandhousesthegeneticmaterial（DNA）onchromosomes.（In

prokaryotesthehereditarymaterialisfoundinthenucleoid.）Thenucleusalsocontainsoneortwoorganelles-the

nucleoli-thatplayaroleincelldivision.Apore-perforatedsaccalledthenuclearenvelopeseparatesthenucleus

anditscontentsfromthecytoplasm.Smallmoleculescanpassthroughthenuclearenvelope,butlargermolecules

suchasmRNAandribosomesmustenterandexitviathepores.

真核細(xì)胞的細(xì)胞核是最大的細(xì)胞器，細(xì)胞核對(duì)染色體組有保護(hù)作用（原核細(xì)胞的遺傳物質(zhì)存在于擬核中）。

細(xì)胞核含有一或二個(gè)核仁，核仁促進(jìn)細(xì)胞分裂。核膜貫穿許多小孔，小分子可以自由通過(guò)核膜，而象mRNA

和核糖體等大分子必須通過(guò)核孔運(yùn)輸。

Organelles:SpecializedWorkUnits（細(xì)胞器：特殊的功能單位）

Alleukaryoticcellscontainmostofthevariouskindsoforganelles,andeachorganelleperformsaspecialized

functioninthecell.Organellesdescribedinthissectionincluderibosomes,theendoplasmicreticulum,theGolgi

complex,vacuoles,lysosomes,mitochondria,andtheplastidsofplantcells.

所有的真核細(xì)胞都含有多種細(xì)胞器，每個(gè)細(xì)胞器都有其特定功能。本節(jié)主要介紹核糖體，內(nèi)質(zhì)網(wǎng)，高爾基

體系，液泡，溶酶體，線粒體和植物細(xì)胞中的質(zhì)體。

Thenumberofribosomeswithinacellmayrangefromafewhundredtomanythousands.Thisquantityreflects

thefactthat,ribosomesarethesitesatwhichaminoacidsareassembledintoproteinsforexportorforuseincell

processes.Acompleteribosomeiscomposedofonelargerandonesmallersubunit.Duringproteinsynthesis

thetwosubunitsmovealongastrandofmRNA,"reading"thegeneticsequencecodedinitandtranslatingthat

sequenceintoprotein.SeveralribosomesmaybecomeattachedtoasinglemRNAstrand;suchacombinationis

calledapolysome.Mostcellularproteinsaremanufacturedonribosomesinthecytoplasm.Exportableproteins

andmembraneproteinsareusuallymadeinassociationwiththeendoplasmicreticulum.

核糖體的數(shù)量變化從幾百到幾千，核糖體是氨基酸組裝成蛋白質(zhì)的重要場(chǎng)所。完整的核糖體由大亞基和小

亞基組成。核糖體沿著mRNA移動(dòng)并閱讀遺傳密碼，翻譯成蛋白質(zhì)。一條mRNA上可能有多個(gè)核糖體，稱

多聚核糖體。大多數(shù)細(xì)胞蛋白是由細(xì)胞質(zhì)中核糖體生產(chǎn)。輸出蛋白和膜蛋白通常與內(nèi)質(zhì)網(wǎng)有關(guān)。

Theendoplasmicreticulum,alacyarrayofmembranoussacs,tubules,andvesicles,maybeeitherrough(RER)or

smooth(SER).Bothtypesplayrolesinthesynthesisandtransportofproteins.TheRER,whichisstuddedwith

polysomes,alsoseemstobethesourceofthenuclearenvelopeafteracelldivides.

內(nèi)質(zhì)網(wǎng)，帶有花邊的生物囊，有管狀，泡狀之分，以及光滑和粗糙面區(qū)別。兩種都與蛋白質(zhì)的合成和運(yùn)輸

有關(guān)。粗糙內(nèi)質(zhì)網(wǎng)上分布許多核糖體，也可能提供細(xì)胞分裂后所需的細(xì)胞膜。

SERlackspolysomes;itisactiveinthesynthesisoffatsandsteroidsandintheoxidationoftoxicsubstancesinthe

cell.Bothtypesofendoplasmicreticulumserveascompartmentswithinthecellwherespecificproductscanbe

isolatedandsubsequentlyshuntedtoparticularareasinoroutsidethecell.

光滑內(nèi)質(zhì)網(wǎng)上無(wú)核糖體，主要作用是脂肪和類(lèi)固醇的合成以及細(xì)胞內(nèi)有毒物質(zhì)的氧化。兩種內(nèi)質(zhì)網(wǎng)合成的

產(chǎn)物在其中進(jìn)行分流或運(yùn)輸?shù)郊?xì)胞外。

Transportvesiclesmaycarryexportablemoleculesfromtheendoplasmicreticulumtoanothermembranous

organelle,theGolgicomplex.WithintheGolgicomplexmoleculesaremodifiedandpackagedforexportoutof

thecellorfordeliveryelsewhereinthecytoplasm.

運(yùn)輸小泡能夠?qū)⒖蛇\(yùn)輸分子從內(nèi)質(zhì)網(wǎng)運(yùn)輸?shù)礁郀柣鶑?fù)合體上。在高爾基復(fù)合體中修飾，包裝后輸出細(xì)胞或

傳遞到細(xì)胞質(zhì)中的其他場(chǎng)所。

Vacuolesincellsappeartobehollowsacsbutareactuallyfilledwithfluidandsolublemolecules.Themost

prominentvacuolesappearinplantcellsandserveaswaterreservoirsandstoragesitesforsugarsandother

molecules.Vacuolesinanimalcellscarryoutphagocytosis(theintakeofparticulatematter)andpinocytosis

(vacuolardrinking).

細(xì)胞中的液泡好象是中空的，但實(shí)際上充滿了液體和可溶分子。最典型的液泡存在于植物細(xì)胞中，儲(chǔ)備水，

糖以及其它分子。動(dòng)物中的液泡起吞噬和胞飲作用。

Asubsetofvacuolesaretheorganellesknownaslysosomes,whichcontaindigestiveenzymes(packagedin

lysosomesintheGolgicomplex)thatcanbreakdownmostbiologicalmacromolecules.Theyacttodigestfood

particlesandtodegradedamagedcellparts.

溶酶體是液泡亞單位，含有消化酶，降解大部分生物大分子。消化食物微粒和降解損傷的細(xì)胞殘片。

Mitochondriaarethesitesofenergy-yieldingchemicalreactionsinallcells.Inaddition,plantcellscontain

plastidsthatutilizelightenergytomanufacturecarbohydratesintheprocessofphotosynthesis.Itisonthelarge

surfaceareaprovidedbytheinnercristaeofmitochondriathatATP-generatingenzymesarelocated.

Mitochondriaareself-replicating,andprobablytheyaretheevolutionarydescendantsofwhatwereoncefree-living

prokaryotes.

線粒體是細(xì)胞中化學(xué)產(chǎn)能的場(chǎng)所。另外，植物細(xì)胞中的質(zhì)體在光合作用中利用光能產(chǎn)生碳水化合物，線粒

體內(nèi)崎上提供了很大的表面積并分布著產(chǎn)ATP酶。線粒體自我復(fù)制，并且可能是自由生活的原核生物在進(jìn)

化中形成的后代。

Therearetwotypesofplastids:leucoplasts,whichlackpigmentsandserveasstoragesitesforstarch,proteins,and

oils;andchromoplasts,whichcontainpigments.Themostimportantchromoplastsarechloroplasts-organelles

thatcontainthechlorophyllusedinphotosynthesis.Theinternalstructureofchloroplastsincludesstacksof

membranescalledgrana,whichareembeddedinamatrixcalledthestroma.

質(zhì)體有兩種類(lèi)型：白色體，缺乏色素，是淀粉，蛋白質(zhì)和油的儲(chǔ)備場(chǎng)所；色質(zhì)體，含有色素。葉綠體是最

重要的色質(zhì)體，含有與光合作用有關(guān)的葉綠素。葉綠體的內(nèi)部結(jié)構(gòu)是由多層膜形成的葉綠體基粒，其中包

埋在基質(zhì)中的基粒稱子座。

TheCytoskeleton（細(xì)胞骨架）

Alleukaryoticcellshaveacytoskeleton,whichisaconvolutedlatticeworkoffilamentsandtubulesthatappearsto

fillallavailablespaceinthecellandprovidessupportforvariousotherorganelles.Alargeportionofthe

cytoskeletonconsistsofthreadlikemicrofilamentscomposedmainlyofthecontractileproteinactin.Theyare

involvedinmanytypesofintracellularmovementsinplantandanimalcells.Asecondprotein,myosin,isinvolve

inthecontractionofmusclecells.Anothermainstructuralcomponentofthecytoskeletonconsistsof

microtubules,whicharecomposedoftheglobularproteintubulinandtogetheractasscaffoldingthatprovidesa

stablecellshape.Cytoskeletalintermediatefilamentsappeartoimparttensilestrengthtothecellcytoplasm.

Mechanoenzymessuchasmyosin,dynein,andkinesininteractwiththecytoskeletalfilamentsandtubulesto

generateforcesthatcausemovements.

所有的細(xì)胞都有細(xì)胞骨架，網(wǎng)絡(luò)結(jié)構(gòu)的纖絲充滿了它所能觸及的全部空間并且對(duì)細(xì)胞器提供支持作用。細(xì)

胞骨架大部分由微絲組成，微絲主要由可收縮的肌動(dòng)蛋白組成。動(dòng)植物細(xì)胞的許多種類(lèi)型細(xì)胞內(nèi)運(yùn)動(dòng)與肌

動(dòng)蛋白有關(guān)。第二類(lèi)蛋白是肌球蛋白，它與肌肉細(xì)胞的收縮有關(guān)。細(xì)胞骨架的另一個(gè)主要結(jié)構(gòu)成分是微管，

由球狀的微管蛋白組成，象腳手架一般維持細(xì)胞的穩(wěn)定形態(tài)。細(xì)胞骨架的中間絲提供了細(xì)胞質(zhì)伸縮動(dòng)力。

機(jī)械酶，例如，肌球蛋白，動(dòng)力蛋白，驅(qū)動(dòng)蛋白與微絲，微管相互作用產(chǎn)生動(dòng)力而引起細(xì)胞運(yùn)動(dòng)。

CellularMovements（細(xì)胞運(yùn)動(dòng)）

Althoughthecytoskeletonprovidessomestabilitytocells,itsmicrotubulesandfilamentsandtheirassociated

proteinsenablecellstomovebycreepingorgliding.Suchmovementsrequireasolidsubstratetowhichthecell

canadhereandcanbeguidedbythegeometryofthesurface.Somecellsalsoexhibitchemotaxis,theabilityto

movetowardorawayfromthesourceofadiffusingchemical.

盡管細(xì)胞骨架提供了細(xì)胞的某些穩(wěn)定性，微絲，微管及相關(guān)蛋白能使細(xì)胞爬行或滑動(dòng)。這種運(yùn)動(dòng)需要固體

基質(zhì)依托并通過(guò)表面幾何形狀的改變而運(yùn)動(dòng)。某些細(xì)胞具備趨藥性，即趨向或逃離擴(kuò)散開(kāi)的化學(xué)源。

Certaineukaryoticcellscanswimfreelyinliquidenvironments,propelledbywhiplikeciliaorflagella.Bothcilia

andflagellahavethesameinternalstructure:ninedoublets（pairsofmicrotubules）arearrangedinaringandextend

thelengthoftheciliumorflagellum,andtwomoremicrotubulesrundownthecenterofthering.Everyciliumor

flagellumgrowsonlyfromthecellsurfacewhereabasalbodyislocated.Movementisbasedontheactivitiesof

tinydyneinsidearmsthatextendfromoneofthemicrotubulesofeachdoublet.

某些真核細(xì)胞能在液體液體中自山運(yùn)動(dòng)，山纖毛或鞭毛推動(dòng)。纖毛和鞭毛具有同樣的內(nèi)部結(jié)構(gòu)：九個(gè)雙微

管環(huán)形排列，縱向延伸，環(huán)中心是兩個(gè)或以上微管組成。纖毛或鞭毛從細(xì)胞表面的基體出生長(zhǎng)，雙微管的

動(dòng)力蛋白臂從一側(cè)延伸到另一側(cè)而引起運(yùn)動(dòng)。

Nutrients,proteins,andothermaterialswithinmostplantcellsaremovedaboutviacytoplasmicstreaming.

Theprocessoccursasmyosinproteinsattachedtoorganellespushagainstmicrofilamentsarrayedthroughoutthe

cell.Microfilamentsandmicrotubulesareresponsibleforalmostallmajorcytoplasmicmovements.Duringcell

division,microtubulesofthespindleassembledfromtubutinsubunitsnearorganellescalledcentriolesmovethe

chromosomes.

大部分植物細(xì)胞的營(yíng)養(yǎng)，蛋白質(zhì)和其它物質(zhì)由細(xì)胞質(zhì)流運(yùn)輸。這個(gè)過(guò)程是由于依附在細(xì)胞器上的肌球蛋白

反推排列在細(xì)胞周?chē)奈⒔z形成的。絕大部分細(xì)胞質(zhì)運(yùn)動(dòng)由微絲和微管完成。在細(xì)胞分裂期間，中心粒周

圍的由微管蛋白亞基裝配形成的紡錘體微管移向染色體。

課后作業(yè)：第一第二篇閱讀材料

答案：IB,2C,3B,4B,5D,6C;1A,2B,3D,4A

Glossary

cytoplasm（細(xì)）胞質(zhì)

Thelivingcontentsofacellboundedexternallybytheplasmalemma,includinganaqueousgroundsubstance

（hyaloplasm,cellsap,orcellmatrix）containingorganellesandvariousinclusionsbutexcludingthenucleusand

visiblevacuoles.

cytoskeleton細(xì)胞骨架

Ofeukaryoticcells,aninternal"skeleton".Itsmicrotubulesandothercomponentsstructurallysupportthecell,

organizeandmoveitsinteftialcomponents.Thecytoskeletonalsohelpsfree-livingcellsmovethroughtheir

environment.

nucleus細(xì)胞核，核（復(fù)數(shù)nuclei）

Theorganelleoftheeukaryotecellthatcontainsthechromosomesandhenceultimatelycontrolscellular

activityandinheritancethroughtheactivityofthegeneticmaterial,DNA

chromosome染色體

ADNA-histonethreadresidinginthenucleusofacell.Eachchromosomepossessestwotelomeresanda

centromere,andsomecontainanucleolusorganize匚RNAproteinsareinvariablyassociatedwiththe

chromosome.

nucleoid擬核，類(lèi)核，核質(zhì)體

TheDNA-containingareaofaprokaryotecell,analogoustotheeukaryotenucleusbutnotmembranebounded.

nucleoli核仁（單數(shù)nucleolus）

Nuclearstructurescomposedofcompletedorpartiallycompletedribosomesandthespecificpartsofchromosomes

thatcontaintheinfon-nationfortheirconstruction.

nuclearenvelope核膜，核被膜

Adoublemembrane（twolipidbilayersandassociatedproteins）thatistheoutermostportionofacellnucleus.

ribosome核糖體

Smallstructurescomposedoftwoproteinandribonucleicacidsubunitsinvolvedintheassemblyofproteinsfrom

aminoacids.

polysome多核糖體

Ofproteinsynthesis,severalribosomesalltranslatingthesamemessengerRNAmolecule,oneaftertheother.

endoplasmicreticulum內(nèi)質(zhì)網(wǎng)

Foldedmembranesandtubesthroughouttheeukaryoticcellthatprovidealargesurfaceuponwhichchemical

activitiestakeplace.

Golgicomplex高爾基復(fù)合體

Astackofflattened,smooth,membranoussacs;thesiteofsynthesisandpackagingofcertainmoleculesin

eukaryoticcells.

vacuole液泡

Storagecontainerwithinthecytoplasmofacellhavingasurroundingmembrane.

phagocytosis吞噬作用

Theprocessbywhichthecellwrapsaroundaparticleandengulfsit.

pinocytosis胞飲作用

Theprocessbywhichacellengulfssomemoleculesdissolvedinwater

lysosome溶酶體

Aspecializedorganellethatholdsamixtureofhydrolyticenzymes.

mitochondrion線粒體（復(fù)數(shù)mitochondria）Amembranousorganelleresemblingasmallbagwithalarger

bagresemblingasmallbagwithalargerbaginsidethatisfoldedbackonitself;servesasthesiteofaerobic

cellularrespiration.

plastid質(zhì)體

Anorganellepresentinallplantsexceptbacteria,blue-greenalgae,andfungi;itisenclosedbytwomembranes（the

envelope）andhasvariousfunctions

chloroplast葉綠體

Aplastidinwhichphotosynthesisiscarriedout.Chloroplastsoccurinallphotosyntheticorganismsexcept

photosyntheticbacteriablue-greenalgae.

stroma基質(zhì)，子座（復(fù)數(shù)stromata）

Regionwithinachloroplastthathasnochlorophyll.

microfilament微絲，纖絲

Long,fiberlikestructuresmadeofproteinandfoundincells,oftenincloseassociationwiththemicrotubules;

providestructuralsupportandenablemovement.

actin肌動(dòng)蛋白

Aglobularcontractileprotein.Inmusclecells,actininteractswithanotherprotein,myosin,tobringabout

contraction.

myosin「maiesin]肌球蛋白

Aproteinthat,withactin,constitutestheprincipalelementofthecontractileapparatusofmuscle.

microtubute微管

Small,hollowtubesofproteinthatfunctionthroughoutthecytoplasmtoprovidestructuralsupportandenable

movement.

tubulin微管蛋白

Aproteinthatisthemajorconstituentofmicrotubules.

dynein動(dòng)力蛋白，動(dòng)素

Agroupofatleastfourdistinctproteinsfoundintheflagellaandmicrotubulesofeukaryoticcellsandpossessing

ATPaseactivity.

chemotaxis趨化性

Alocomotorymovementofanorganismorcellinresponseto,anddirectedby,andirectionalstimulus.

cilia纖毛

Numerousshort,hairlikestructuresprojectingfromthecellsurfacethatenablelocomotion.

flagella鞭毛（單數(shù)flagellum）

Long,hairlikestructuresprojectingfromthecellsurfacethatenablelocomotion.

basalbody基體

Abodyidenticalinstructuretoacentriole,foundalwaysatthebaseofaciliumoreukaryoteflagellum,

centriole中心粒

Anorganellelocatedclosetothenucleusinmostanimalandlowerplantcellsbutabsentfromprokaryotesand

higherplants.

LessonTwo(2學(xué)時(shí))

Photosynthesis

教學(xué)目的：使學(xué)生掌握細(xì)胞的光合作用機(jī)理，光合系統(tǒng)I與光合系統(tǒng)H結(jié)構(gòu)與功能之間的關(guān)系。相關(guān)英語(yǔ)

詞匯以及主要用法。

教學(xué)重點(diǎn)：光合作用中相關(guān)的概念和功能，及相關(guān)英語(yǔ)詞匯的掌握

教學(xué)難點(diǎn)：專業(yè)英語(yǔ)詞匯的記憶

講授方法：以學(xué)生翻譯為主，老師講解相關(guān)專業(yè)知識(shí)輔助學(xué)生理解

授課忖間：4月5日

教學(xué)內(nèi)容：

Photosynthesisoccursonlyinthechlorophyll-containingcellsofgreenplants,algae,andcertainprotistsand

bacteria.Overall,itisaprocessthatconvertslightenergyintochemicalenergythatisstoredinthemolecular

bonds.Fromthepointofviewofchemistryandenergetics,itistheoppositeofcellularrespiration.Whereas

cellularrespirationishighlyexergonicandreleasesenergy,photosynthesisrequiresenergyandishighly

endergonic.

光合作用只發(fā)生在含有葉綠素的綠色植物細(xì)胞，海藻，某些原生動(dòng)物和細(xì)菌之中?？傮w來(lái)說(shuō)，這是一個(gè)將

光能轉(zhuǎn)化成化學(xué)能，并將能量貯存在分子鍵中，從化學(xué)和動(dòng)能學(xué)角度來(lái)看，它是細(xì)胞呼吸作用的對(duì)立面。

細(xì)胞呼吸作用是高度放能的，光合作用是需要能量并高吸能的過(guò)程。

PhotosynthesisstartswithCO2andH20asrawmaterialsandproceedsthroughtwosetsofpartialreactions.In

thefirstset,calledthelight-dependentreactions,watermoleculesaresplit(oxidized),02isreleased,andATPand

NADPHareformed.Thesereactionsmusttakeplaceinthepresenceoflightenergy.Inthesecondset,called

light-independentreactions,CO2isreduced(viatheadditionofHatoms)tocarbohydrate.Thesechemicalevents

relyontheelectroncarrierNADPHandATPgeneratedbythefirstsetofreactions.

光合作用以二氧化碳和水為原材料并經(jīng)歷兩步化學(xué)反應(yīng)。第一步，稱光反應(yīng)，水分子分解，氧分子釋放，

ATP和NADPH形成。此反應(yīng)需要光能的存在。第二步，稱暗反應(yīng)，二氧化碳被還原成碳水化合物，這步

反應(yīng)依賴電子載體NADPH以及第一步反應(yīng)產(chǎn)生的ATP。

Bothsetsofreactionstakeplaceinchloroplasts.Mostoftheenzymesandpigmentsforthelightdependent

reactionsareembeddedinthethylakoidmembraneofchloroplasts.Thedarkreactionstakeplaceinthestroma.

兩步反應(yīng)都發(fā)生在葉綠體中。光反應(yīng)需要的大部分酶和色素包埋在葉綠體的類(lèi)囊體膜上。暗反應(yīng)發(fā)生在基

質(zhì)中。

HowLightEnergyReachesPhotosyntheticCells(光合細(xì)胞如何吸收光能的)

Theenergyinlightphotonsinthevisiblepartofthespectrumcanbecapturedbybiologicalmoleculestodo

constructivework.Thepigmentchlorophyllinplantcellsabsorbsphotonswithinaparticularabsorption

spectrumsstatementoftheamountoflightabsorbedbychlorophyllatdifferentwavelengths.Whenlightis

absorbeditaltersthearrangementofelectronsintheabsorbingmolecule.Theaddedenergyofthephotonboosts

theenergyconditionofthemoleculefromastablestatetoaless-stableexcitedstate.Duringthelight-dependent

reactionsofphotosynthesis,astheabsorbingmoleculereturnstothegroundstate,the"excess"excitationenergyis

transmittedtoothermoleculesandstoredaschemicalenergy.

生物分子能捕獲可見(jiàn)光譜中的光能。植物細(xì)胞中葉綠素在不同光波下吸收部分吸收光譜。在吸收分子中，

光的作用使分子中的電子發(fā)生重排。光子的能量激活了分子的能量狀態(tài)，使其從穩(wěn)定態(tài)進(jìn)入不穩(wěn)定的激活

態(tài)。

Allphotosyntheticorganismscontainvariousclassesofchlorophyllsandoneormorecarotenoid(accessory)

pigmentsthatalsocontributetophotosynthesis.Groupsofpigmentmoleculescalledantennacomplexesare

presentonthylakoids.Lightstrikinganyoneofthepigmentmoleculesisfunneledtoaspecialchlorophylla

molecule,termedareaction-centerchlorophyll,whichdirectlyparticipatesinphotosynthesis.Most

photosyntheticorganismspossesstwotypesofreaction-centerchlorophylls,P680andP700,eachassociatedwith

anelectronacceptormoleculeandanelectrondonor.Theseaggregationsareknownrespectivelyasphotosystem

I(P700)andphotosystemII(P680).

所有的光合作用生物含有不同等級(jí)的葉綠素和一個(gè)或多個(gè)類(lèi)胡蘿卜素(光合作用的輔助色素)。稱作天線復(fù)

合體的色素分子群存在于類(lèi)囊體中。激活色素分子的光能進(jìn)入葉綠素反應(yīng)中心，其直接參與光合作用。大

部分光反應(yīng)細(xì)胞器擁有兩套反應(yīng)中心，P680和P700,每個(gè)光系統(tǒng)都含有一個(gè)電子受體和電子供體。這些集

合體就是大家熟識(shí)的光合系統(tǒng)I和光合系統(tǒng)

TheLight-DependentReaction:ConvertingSolarEnergyintoChemical-BondEnergy

光反應(yīng)：光能轉(zhuǎn)化成化學(xué)鍵能

Thephotosystemsofthelight-dependentreactionsareresponsibleforthepackagingoflightenergyinthecheinical

compoundsATPandNADPH.Thispackagingtakesplacethroughaseriesofoxidationreductionreactionssetin

motionwhenlightstrikestheP680reactioncenterinphotosystemII.Inthisinitialeventwatermoleculesare

cleaved,oxygenisreleased,andelectronsaredonated.Theseelectronsareacceptedfirstbyplastoquinoneand

thenbyaseriesofcarriersastheydescendanelectrontransportchain.Foreachfourelectronsthatpassdownthe

chain,twoATPsareformed.ThelastacceptorinthechainistheP700reactioncenterofphotosystemI.Atthis

pointincomingphotonsboosttheenergyoftheelectrons,andtheyareacceptedbyferredoxin.Ferredoxinisthen

reoxidized,andthecoenzymeNADP+isreducedtotheNADPH.TheATPgeneratedpreviouslyandtheNADPH

thentakepartinthelightindependentreactions.

光反應(yīng)的光系統(tǒng)將光能轉(zhuǎn)化成化學(xué)復(fù)合物ATP和NADPHo當(dāng)光激活光系統(tǒng)II的光反應(yīng)中心時(shí)，通過(guò)一系

列的氧化還原反應(yīng)實(shí)現(xiàn)能量的傳遞。反應(yīng)開(kāi)始時(shí)，水被分解，氧被釋放并提供電子。電子首先傳遞給質(zhì)體

醍，然后通過(guò)一系列載體形成的電子傳遞鏈。每傳遞4個(gè)電子，形成2個(gè)ATP。最后一個(gè)受體存在于光反

應(yīng)系統(tǒng)I的反應(yīng)中心里。此處光子激活電子，電子傳遞給鐵氧還蛋白。鐵氧還蛋白再氧化，并且輔酶NADP+

還原成NADPHo早期產(chǎn)生的ATP和NADPH進(jìn)入暗反應(yīng)。

TheproductionofATPfromthetransportofelectronsexcitedbylightenergydownanelectrontransportchainis

termedphotophosphorylation.Theone-wayflowofelectronsthroughphotosystemsIIandIiscallednoncyclic

photophosphorylation;plantsalsoderiveadditionalATPthroughcyclicphotophosphorylation,inwhichsome

electronsareshuntedbackthroughtheelectrontransportchainbetweenphotosystemsIIandI.

由電子傳遞鏈偶連產(chǎn)生ATP的過(guò)程稱為光合磷酸化。通過(guò)光合系統(tǒng)H流經(jīng)光合系統(tǒng)I的電子路徑稱非循環(huán)

式光合磷酸化；植物通過(guò)循環(huán)式光合磷酸化獲得額外的ATP,一些電子在光合系統(tǒng)I和II之間的電子傳遞

鏈中回流。

TheLight-IndependentReactions:BuildingCarbohydrates

暗反應(yīng)：碳水化合物的形成

Inthelight-independentreactionsofphotosynthesis,whicharedrivenbyATPandNADPH,C02isconvertedto

carbohydrate.ThereactionsarealsoknownastheCalvin-Bensoncycle.AtmosphericC02,isfixedasitreacts

withribulosebiphosphate(RuBP),areactionthatiscatalyzedbytheenzymeribulosebiphosphatecarboxylase.

ThereductionOfC02tocarbohydrate(fructosediphosphate)iscompletedviaseveralmorestepsofthecycle.

Finally,RUBPisregeneratedsothatthecyclemaycontinue.

由ATP和NADPH驅(qū)動(dòng)的暗反應(yīng)中，二氧化碳轉(zhuǎn)化成碳水化合物。即卡爾文循環(huán)。二磷酸核酮糖固定二氧

化碳，由二磷酸核酮糖竣化酶催化。

Oxygen:AnInhibitorofphotosynthesis(氧:光合作用的抑制因子)

Highlevelsofoxygeninplantcellscandisruptphotosynthesisandcanalsocausephotorespiration-aninefficient

funofthedarkreactionsinwhich02isfixedratherthanC02andnocarbohydrateisproduced.

ReprievefromPhotorespiration:TheC4Pathway

MostplantsareC3plants;theyexperiencedecreasedcarbohydrateproductionunderhot,dryconditionsasaresult

oftheeffectsofphotorespiration.AmongC4plants,however,specialleafanatomyandauniquebiochemical

pathwayenabletheplanttothriveinandconditions.ThusC4plantslessenphotorespirationbycarryingout

photosynthesisonlyincellsthatareinsulatedfromhighlevelsofCO2.Theyalsopossessanovelmechanismfor

carbonfixation.

大部分植物是碳3植物，在高溫干旱條件下，由于光呼吸作用而使碳水化合物的合成降低。而在大多數(shù)的

碳4植物中，由于葉脈的特殊構(gòu)造和獨(dú)特的化學(xué)路徑使植物依然很茂盛。這是碳固定的一個(gè)新機(jī)制。

課后作業(yè)：第一篇閱讀材料

答案：lB,2A,3A,4D,5C,6c

Glossary

light-dependentreactions光反應(yīng)?

Thefirststageinphotosynthesis,drivenbylightenergy.Electronsthattrapthesun'senergypasstheenergyto

high-energycarrierssuchasATPorNADPH,whereitisstoredinchemicalbonds,

light-independentreactions暗反應(yīng)

Thesecondstageofphotosynthesis,alsocalledtheCalvin-Bensoncycle,whichdoesnotrequirelight.Duringthe

sixstepsofthecycle,carbonisfixedandcarbohydratesareformed,

chloroplast葉綠體

Aplastidinwhichphotosynthesisiscarriedout.Chloroplastsoccurinallphotosyntheticorganismsexcept

photosyntheticbacteriaandblue-greenalgae.

absorptionspectrum吸收光譜，吸收譜

Thespectrumobtainedwhenradiation(light,ultravioletradiation,etc.)fromasourcegivingacontinuousspectrum

ispassedthroughasubstance.

Calvin-Bensoncycle卡爾文?本森循環(huán)

Cyclicreactionsthatarethe"synthesis“partofthelight-independentreactionsofphotosynthesis.Inlandplants,

RUBP,orsomeothercompoundtowhichcarbonhas

beenaffixed,undergoesrearrangementsthatleadtoformationofasugarphosphateandtoregenerationofthe

RUBP.ThecyclerunsonATPandNADPHfromlight-dependentreactions,

carotenoid類(lèi)胡蘿卜素

Light-sensitive,accessorypigmentsthattransferabsorbedenergytochlorophylls.Theyabsorbvioletandblue

wave-lengthsbuttransmitred,orange,andyellow.

chlorophyll葉綠素

Thegreensubstanceofplantsbywhichphotosynthesisisaccomplished;itisusuallylocalizedinintracellular

organellescalledchloroplasts.

cyclicphotophosphorylation

環(huán)形光合磷酸化(作用)

Cyclicphotophosphorylationiscoupledtocyclicelectronflow,inwhichATPistheonlyproduct.

C3plant三碳植物

Aplantinwhichthelight-independentreactionsofphotosynthesisstartwithathreecarboncompound.Most

plantsareC3plants.

C4plant四碳植物

Aplantsuchascorninwhichthelightindependentreactionsofphotosynthesisstarwithafour-carboncompound.

noncyclicphotophosphorylation

非環(huán)形光合磷酸化作用

Noncyclicphotophosphorylationiscoupledtononcyclicelectronflow,theelectronsbeingusedtoreduceNADP+

aswellastomakeATP.

photon光子

Aparticlethathaszeromassorchargeandunitspin,thequantumoftheelectromagneticfieldandcarrierofthe

electromagneticforce.

photophosphorylation光合磷酸化作用

ThesynthesisofATPfromphosphateandADPduringphotosynthesis,usinglightenergy,

photorespiration光呼吸

Alight-dependenttypeofrespirationthatoccursinmostphotosyntheticplantsanddiffersfromnormal(ordark)

respiration.

photosynthesis光合作用

Thesynthesisoforganiccompoundsbyreductionofcarbondioxideusinglightenergyabsorbedbychorophyll.

photosystem光合系統(tǒng)

Oneoftheclustersoflight-trappingpigmentsembeddedinphotosyntheticmembranes.PhotosystemIoperates

duringthecyclicpathway;photosystemIIoperatesduringboththecyclicandnoncyclicpathways,

ribulosebiphosphate(RUBP)核酮糖二磷酸

AcompoundwithabackboneoffivecarbonatomsthatisrequiredforcarbonfixationintheCalvin-Bensoncycle

ofphotosynthesis.

thylakoid類(lèi)囊體

Oneofanumberofflattenedfluid-filledsacsthatformthephotosyntheticlamellarsystemofchloroplasts,

photosyntheticbacteria,andblue-greenalgae.

LessonThree(2學(xué)時(shí))

CellularReproduction:MitosisandMeiosis

教學(xué)目的：使學(xué)生掌握細(xì)胞的有絲分裂和無(wú)絲分裂的作用機(jī)理，有絲分裂和無(wú)絲分裂之間的區(qū)別和相同點(diǎn)。

相關(guān)英語(yǔ)詞匯以及主要用法。

教學(xué)重點(diǎn)：有絲分裂和無(wú)絲分裂中相關(guān)的概念和功能，及相關(guān)英語(yǔ)詞匯的掌握

教學(xué)難點(diǎn)：專業(yè)英語(yǔ)詞匯的記憶

講授方法：以學(xué)生翻譯為主，老師講解相關(guān)專業(yè)知識(shí)輔助學(xué)生理解

授課時(shí)間：4月12日

教學(xué)內(nèi)容：

TheNucleusandChromosomes

Thecellnucleusisthemainrepositoryofgeneticinformation.Withinthenucleusarethechromosomestightly

coiledstrandsofDNAandclustersofassociatedproteins.LongstretchesofthecontinuousDNAmoleculewind

aroundtheseclustersofproteins,orhistones,formingbeadlikecomplexesknownasnucleosomes.Morecoiling

andsupercoilingproducesadensechromosomestructure.EachlongstrandofDNAcombineswithhistonesand

nonhistoneproteinstomakeupthesubstancechromatin.

細(xì)胞核是貯藏遺傳信息的主要場(chǎng)所。DNA盤(pán)繞成螺旋線以及相關(guān)的成簇蛋白質(zhì)。DNA螺旋線纏繞成簇的組

蛋白形成珠鏈狀的核小體。這些螺旋和超螺旋形成致密的染色體組結(jié)構(gòu)。每個(gè)長(zhǎng)鏈DNA與組蛋白和非組蛋

白?起構(gòu)成染色質(zhì)物質(zhì)。

Apictorialdisplayofanorganism'schromosomesinthecoiled,condensedstateisknownasakaiyotype.

Karyotyperevealthatinmostcellsallbutsexchromosomesarepresentastwocopies,referredtoashomologous

pairs.Non-sexchromosomesarecalledautosomes.Organismswhosecellscontaintwosetsofparental

chromosomesarecalleddiploid;thosewithcellscontainingasinglesetofparentalchromosomesarecalled

haploid.

染色體致密的超螺旋狀態(tài)我們稱染色體組。除了性染色體外，大多數(shù)細(xì)胞的染色體組成對(duì)出現(xiàn)，稱同源染

色體對(duì)。非性染色體稱常染色體。生物細(xì)胞含有兩套父母本染色體的稱二倍體；含有單套染色體的稱單倍

體。

TheCellCycle

Thecellcycleisaregularsequenceinwhichthecellgrows,preparesfordivision,anddividestoformtwodaughter

cells,eachofwhichthenrepeatsthecycle.Suchcyclingineffectmakessingle-celledorganismsimmortal.

Manycellsinmulticellularorganisms,includinganimalmuscleandnervecells,eitherslowthecycleorbreakout

ofitaltogether.

在細(xì)胞生長(zhǎng)過(guò)程中，細(xì)胞循環(huán)遵循特定程序，分裂準(zhǔn)備，分裂成2個(gè)子細(xì)胞，子細(xì)胞再循環(huán)。此循環(huán)使得

單細(xì)胞永生。多細(xì)胞生物中的許多細(xì)胞，包括動(dòng)物肌肉和神經(jīng)細(xì)胞，要么降低循環(huán)速度，要么同時(shí)分裂。

Thenormalcellcycleconsistsoffourphases.ThefirstthreeincludeGl,theperiodofnormalmetabolism;S

phase,duringwhichnormalsynthesisofbiologicalmoleculescontinues,DNAisreplicated,andhistonesare

synthesized;andG2,abriefperiodofmetabolismandadditionalgrowth.TogethertheG1,S,andG2phasesare

calledinterphase.ThefourthphaseofthecellcycleisMphase,theperiodofmitosis,duringwhichthereplicated

chromosomescondenseandmoveandthecelldivides.Itisbelievedthatpropertiesofthecellcytoplasmcontrol

thecellcycle,alongwithexternalstimulatorsandinhibitorssuchaschalones.

正常細(xì)胞循環(huán)由4個(gè)時(shí)期組成。頭三期包括G1,正常新陳代謝：S期,正常新陳代謝同時(shí)，DNA復(fù)制，組蛋

白合成；G2期，短期的新陳代謝和少許生長(zhǎng)。G1.S,和G2稱分裂間期。最后是M期，有絲分裂期，復(fù)

制的染色體組濃縮，移動(dòng)并細(xì)胞分裂。據(jù)稱是染色質(zhì)控制了細(xì)胞循環(huán)，伴隨外部激活因子和抑制因子如抑

素。

Mitosis:PartitioningtheHereditaryMaterial

Biologistsdividethemitoticcycleintofourphases.Atthebeginningofprophasethechromosomeseachconsist

oftwohighlycondensedchromatidsattachedtoeachotheratacentromere.Asprophaseendsandmetaphase

begins,thecondens