《生物專業(yè)英語》教學(xué)案

《生物專業(yè)英語》

教學(xué)案

《生物專業(yè)英語》教/學(xué)案

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

CellParts

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)胞器以及它們在細(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)英語詞匯的掌握

教學(xué)難點(diǎn)：專業(yè)英語詞匯的記憶

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)：動力工廠

Mostofthepropertiesweassociatewithlifearepropertiesofthecytoplasm.

Muchofthemassofacellconsistsofthissemifluidsubstance,whichisbounded

ontheoutsidebytheplasmamembrane.Organellesaresuspendedwithinit,

supportedbythefilamentousnetworkofthecytoskeleton.Dissolvedinthe

cytoplasmicfluidarenutrients,ions,solubleproteins,andothermaterials

neededforcellfunctioning.

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）

Theeukaryoticcellnucleusisthelargestorganelleandhousesthegenetic

material（DNA）onchromosomes.（Inprokaryotesthehereditarymaterialisfound

inthenucleoid.）Thenucleusalsocontainsoneortwoorganelles-thenucleoli-

thatplayaroleincelldivision.Apore-perforatedsaccalledthenuclear

envelopeseparatesthenucleusanditscontentsfromthecytoplasm.Small

moleculescanpassthroughthenuclearenvelope,butlargermoleculessuchas

mRNAandribosomesmustenterandexitviathepores.

真核細(xì)胞的細(xì)胞核是最大的細(xì)胞器，細(xì)胞核對染色體組有保護(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

可以自由通過核膜，而象mRNA和核糖體等大分子必須通過核孔運(yùn)輸。

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

Alleukaryoticcellscontainmostofthevariouskindsoforganelles,andeach

organelleperformsaspecializedfunctioninthecell.Organellesdescribedin

thissectionincluderibosomes,theendoplasmicreticulum,theGolgicomplex,

vacuoles,lysosomes,mitochondria,andtheplastidsofplantcells.

所有的真核細(xì)胞都含有多種細(xì)胞器，每個細(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。

Thenumberofribosomeswithinacellmayrangefromafewhundredtomany

thousands.Thisquantityreflectsthefactthat,ribosomesarethesitesat

whichaminoacidsareassembledintoproteinsforexportorforuseincell

processes.Acompleteribosomeiscomposedofonelargerandonesmallersubunit.

DuringproteinsynthesisthetwosubunitsmovealongastrandofmRNA,"reading”

thegeneticsequencecodedinitandtranslatingthatsequenceintoprotein.

SeveralribosomesmaybecomeattachedtoasinglemRNAstrand；suchacombination

iscalledapolysome.Mostcellularproteinsaremanufacturedonribosomesin

thecytoplasm.Exportableproteinsandmembraneproteinsareusuallymadein

associationwiththeendoplasmicreticulum.

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移動并閱讀遺傳密碼，翻譯成蛋白質(zhì)。一條mRNA

上可能有多個核糖體，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)orsmooth(SER).Bothtypesplayrolesinthe

synthesisandtransportofproteins.TheRER,whichisstuddedwithpolysomes,

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；itisactiveinthesynthesisoffatsandsteroidsandin

theoxidationoftoxicsubstancesinthecell.Bothtypesofendoplasmic

reticulumserveascompartmentswithinthecellwherespecificproductscanbe

isolatedandsubsequentlyshuntedtoparticularareasinoroutsidethecell.

光滑內(nèi)質(zhì)網(wǎng)上無核糖體，主要作用是脂肪和類固醇的合成以及細(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。

Transportvesiclesmaycarryexportablemoleculesfromtheendoplasmicreticulum

toanothermembranousorganelle,theGolgicomplex.WithintheGolgicomplex

moleculesaremodifiedandpackagedforexportoutofthecellorfordelivery

elsewhereinthecytoplasm.

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)中的其他場所。

Vacuolesincellsappeartobehollowsacsbutareactuallyfilledwithfluidand

solublemolecules.Themostprominentvacuolesappearinplantcellsandserve

aswaterreservoirsandstoragesitesforsugarsandothermolecules.Vacuoles

inanimalcellscarryoutphagocytosis(theintakeofparticulatematter)and

pinocytosis(vacuolardrinking).

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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，儲備水，糖以及其它分子。動物中的液泡起吞噬和胞飲作用。

Asubsetofvacuolesaretheorganellesknownaslysosomes,whichcontain

digestiveenzymes(packagedinlysosomesintheGolgicomplex)thatcanbreak

downmostbiologicalmacromolecules.Theyacttodigestfoodparticlesandto

degradedamagedcellparts.

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,plantcellscontainplastidsthatutilizelightenergyto

manufacturecarbohydratesintheprocessofphotosynthesis.Itisonthelarge

surfaceareaprovidedbytheinnercristaeofmitochondriathatATP-generating

enzymesarelocated.Mitochondriaareself-replicating,andprobablytheyare

theevolutionarydescendantsofwhatwereoncefree-livingprokaryotes.

線粒體是細(xì)胞中化學(xué)產(chǎn)能的場所。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)蠟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,whichlackpigmentsandserveas

storagesitesforstarch,proteins,andoils；andchromoplasts,whichcontain

pigments.Themostimportantchromoplastsarechioroplasts-organeIlesthat

containthechlorophyllusedinphotosynthesis.Theinternalstructureof

chloroplastsincludesstacksofmembranescalledgrana,whichareembeddedina

matrixcalledthestroma.

質(zhì)體有兩種類型：白色體，缺乏色素，是淀粉，蛋白質(zhì)和油的儲備場所；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,whichisaconvolutedlatticeworkof

filamentsandtubulesthatappearstofillallavailablespaceinthecelland

providessupportforvariousotherorganelles.Alargeportionofthe

cytoskeletonconsistsofthreadlikemicrofilamentscomposedmainlyofthe

contractileproteinactin.Theyareinvolvedinmanytypesofintracellular

movementsinplantandanimalcells.Asecondprotein,myosin,isinvolveinthe

contractionofmusclecells.Anothermainstructuralcomponentofthe

cytoskeletonconsistsofmicrotubules,whicharecomposedoftheglobularprotein

tubulinandtogetheractasscaffoldingthatprovidesastablecellshape.

Cytoskeletalintermediatefilamentsappeartoimparttensilestrengthtothecell

cytoplasm.Mechanoenzymessuchasmyosin,dynein,andkinesininteractwiththe

cytoskeletalfilamentsandtubulestogenerateforcesthatcausemovements.

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蛋白組成。動植物細(xì)胞的

許多種類型細(xì)胞內(nèi)運(yùn)動與肌動蛋白有關(guān)。第二類蛋白是肌球蛋白，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)

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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)伸縮動力。機(jī)械酶，例如，肌球蛋白，動力

蛋白，驅(qū)動蛋白與微絲，微管相互作用產(chǎn)生動力而引起細(xì)胞運(yùn)動。

CellularMovements(細(xì)胞運(yùn)動)

Althoughthecytoskeletonprovidessomestabilitytocells,itsmicrotubulesand

filamentsandtheirassociatedproteinsenablecellstomovebycreepingor

gliding.Suchmovementsrequireasolidsubstratetowhichthecellcanadhere

andcanbeguidedbythegeometryofthesurface.Somecellsalsoexhibit

chemotaxis,theabilitytomovetowardorawayfromthesourceofadiffusing

chemical.

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。這種

運(yùn)動需要固體基質(zhì)依托并通過表面幾何形狀的改變而運(yùn)動。某些細(xì)胞具備趨藥性，即趨向或

逃離擴(kuò)散開的化學(xué)源。

Certaineukaryoticcellscanswimfreelyinliquidenvironments,propelledby

whiplikeciliaorflagella.Bothciliaandflagellahavethesameinternal

structure：ninedoublets(pairsofmicrotubules)arearrangedinaringand

extendthelengthoftheciliumorflagellum,andtwomoremicrotubulesrundown

thecenterofthering.Everyciliumorflagellumgrowsonlyfromthecell

surfacewhereabasalbodyislocated.Movementisbasedontheactivitiesof

tinydyneinsidearmsthatextendfromoneofthemicrotubulesofeachdoublet.

某些真核細(xì)胞能在液體液體中自由運(yùn)動，由纖毛或鞭毛推動。纖毛和鞭毛具有同樣的內(nèi)部結(jié)

構(gòu)：九個雙微管環(huán)形排列，縱向延伸，環(huán)中心是兩個或以上微管組成。纖毛或鞭毛從細(xì)胞表

面的基體出生長，雙微管的動力蛋白臂從一側(cè)延伸到另一側(cè)而引起運(yùn)動。

Nutrients,proteins,andothermaterialswithinmostplantcellsaremoved

aboutviacytoplasmicstreaming.Theprocessoccursasmyosinproteinsattached

toorganellespushagainstmicrofilamentsarrayedthroughoutthecell.

Microfilamentsandmicrotubulesareresponsibleforalmostallmajorcytoplasmic

movements.Duringcelldivision,microtubulesofthespindleassembledfrom

tubutinsubunitsnearorganellescalledcentriolesmovethechromosomes.

大部分植物細(xì)胞的營養(yǎng)，蛋白質(zhì)和其它物質(zhì)由細(xì)胞質(zhì)流運(yùn)輸。這個過程是由于依附在細(xì)胞

器上的肌球蛋白反推排列在細(xì)胞周圍的微絲形成的。絕大部分細(xì)胞質(zhì)運(yùn)動由微絲和微管完

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：lB,2C,3B,4B,5D,6c；1A,2B,3D,4A

Glossary

cytoplasm(細(xì))胞質(zhì)

Thelivingcontentsofacellboundedexternallybytheplasmalemma,includingan

aqueousgroundsubstance(hyaloplasm,cellsap,orcellmatrix)containing

organellesandvariousinclusionsbutexcludingthenucleusandvisiblevacuoles,

cytoskeleton細(xì)胞骨架

Ofeukaryoticcells,aninternal"skeleton”.Itsmicrotubulesandother

componentsstructurallysupportthecell,organizeandmoveitsinteftial

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components.Thecytoskeletonalsohelpsfree-livingcellsmovethroughtheir

environment.

nucleus細(xì)胞核，核（復(fù)數(shù)nuclei）

Theorganelleoftheeukaryotecellthatcontainsthechromosomesandhence

ultimatelycontrolscellularactivityandinheritancethroughtheactivityofthe

geneticmaterial,DNA

chromosome染色體

ADNA-histonethreadresidinginthenucleusofacell.Eachchromosome

possessestwotelomeresandacentromere,andsomecontainanucleolusorganizer.

RNAproteinsareinvariablyassociatedwiththechromosome,

nucleoid擬核，類核，核質(zhì)體

TheDNA-containingareaofaprokaryotecell,analogoustotheeukaryotenucleus

butnotmembranebounded.

nucleoli核仁（單數(shù)nucleolus）

Nuclearstructurescomposedofcompletedorpartiallycompletedribosomesandthe

specificpartsofchromosomesthatcontaintheinfon-nationfortheir

construction.

nuclearenvelope核膜，核被膜

Adoublemembrane（twolipidbilayersandassociatedproteins）thatisthe

outermostportionofacellnucleus,

ribosome核糖體

Smallstructurescomposedoftwoproteinandribonucleicacidsubunitsinvolved

intheassemblyofproteinsfromaminoacids,

polysome多核糖體

Ofproteinsynthesis,severalribosomesalltranslatingthesamemessengerRNA

molecule,oneaftertheother,

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

Foldedmembranesandtubesthroughouttheeukaryoticcellthatprovidealarge

surfaceuponwhichchemicalactivitiestakeplace.

Golgicomplex高爾基復(fù)合體

Astackofflattened,smooth,membranoussacs；thesiteofsynthesisand

packagingofcertainmoleculesineukaryoticcells,

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）Amembranousorganelleresemblinga

smallbagwithalargerbagresemblingasmallbagwithalargerbaginsidethat

isfoldedbackonitself；servesasthesiteofaerobiccellularrespiration,

plastid質(zhì)體

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Anorganellepresentinallplantsexceptbacteria,blue-greenalgae,andfungi；

itisenclosedbytwomembranes（theenvelope）andhasvariousfunctions

chloroplast葉綠體

Aplastidinwhichphotosynthesisiscarriedout.Chloroplastsoccurinall

photosyntheticorganismsexceptphotosyntheticbacteriablue-greenalgae,

stroma基質(zhì)，子座（復(fù)數(shù)stromata）

Regionwithinachloroplastthathasnochlorophyll.

microfilament微絲，纖絲

Long,fiberlikestructuresmadeofproteinandfoundincells,ofteninclose

associationwiththemicrotubules；providestructuralsupportandenablemovement,

actin肌動蛋白

Aglobularcontractileprotein.Inmusclecells,actininteractswithanother

protein,myosin,tobringaboutcontraction.

myosinfmaiesin]肌球蛋白

Aproteinthat,withactin,constitutestheprincipalelementofthecontractile

apparatusofmuscle,

microtubute微管

Small,hollowtubesofproteinthatfunctionthroughoutthecytoplasmtoprovide

structuralsupportandenablemovement.

tubulin微管蛋白

Aproteinthatisthemajorconstituentofmicrotubules.

dynein動力蛋白，動素

Agroupofatleastfourdistinctproteinsfoundintheflagellaandmicrotubules

ofeukaryoticcellsandpossessingATPaseactivity,

chemotaxis趨化性

Alocomotorymovementofanorganismorcellinresponseto,anddirectedby,an

directionalstimulus.

cilia纖毛

Numerousshort,hairlikestructuresprojectingfromthecellsurfacethatenable

locomotion.

flagella鞭毛（單數(shù)flagellum）

Long,hairlikestructuresprojectingfromthecellsurfacethatenablelocomotion,

basalbody基體

Abodyidenticalinstructuretoacentriole,foundalwaysatthebaseofa

ciliumoreukaryoteflagellum,

centriole中心粒

Anorganellelocatedclosetothenucleusinmostanimalandlowerplantcells

butabsentfromprokaryotesandhigherplants.

LessonTwo（2學(xué)時(shí)）

Photosynthesis

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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)n結(jié)構(gòu)與功能之間的關(guān)

系。相關(guān)英語詞匯以及主要用法。

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

教學(xué)難點(diǎn)：專業(yè)英語詞匯的記憶

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

授課時(shí)間：4月5日

教學(xué)內(nèi)容：

Photosynthesisoccursonlyinthechlorophyll-containingcellsofgreenplants,

algae,andcertainprotistsandbacteria.Overall,itisaprocessthatconverts

lightenergyintochemicalenergythatisstoredinthemolecularbonds.From

thepointofviewofchemistryandenergetics,itistheoppositeofcellular

respiration.Whereascellularrespirationishighlyexergonicandreleases

energy,photosynthesisrequiresenergyandishighlyendergonic.

光合作用只發(fā)生在含有葉綠素的綠色植物細(xì)胞，海藻，某些原生動物和細(xì)菌之中。總體來

說，這是一個將光能轉(zhuǎn)化成化學(xué)能，并將能量貯存在分子鍵中，從化學(xué)和動能學(xué)角度來看，

它是細(xì)胞呼吸作用的對立面。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

過程。

PhotosynthesisstartswithC02andH20asrawmaterialsandproceedsthroughtwo

setsofpartialreactions.Inthefirstset,calledthelight-dependent

reactions,watermoleculesaresplit(oxidized),02isreleased,andATPand

NADPHareformed.Thesereactionsmusttakeplaceinthepresenceoflight

energy.Inthesecondset,calledlight-independentreactions,C02isreduced

(viatheadditionofHatoms)tocarbohydrate.Thesechemicaleventsrelyonthe

electroncarrierNADPHandATPgeneratedbythefirstsetofreactions.

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ATPo

Bothsetsofreactionstakeplaceinchloroplasts.Mostoftheenzymesand

pigmentsforthelightdependentreactionsareembeddedinthethylakoidmembrane

ofchloroplasts.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)

Theenergyinlightphotonsinthevisiblepartofthespectrumcanbecaptured

bybiologicalmoleculestodoconstructivework.Thepigmentchlorophyllin

plantcellsabsorbsphotonswithinaparticularabsorptionspectrumsstatementof

theamountoflightabsorbedbychlorophyllatdifferentwavelengths.Whenlight

isabsorbeditaltersthearrangementofelectronsintheabsorbingmolecule.

Theaddedenergyofthephotonbooststheenergyconditionofthemoleculefroma

stablestatetoaless-stableexcitedstate.Duringthelight-dependent

reactionsofphotosynthesis,astheabsorbingmoleculereturnstotheground

state,the"excess"excitationenergyistransmittedtoothermoleculesand

storedaschemicalenergy.

7

生物分子能捕獲可見光譜中的光能。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)。

Allphotosyntheticorganismscontainvariousclassesofchlorophyllsandoneor

morecarotenoid(accessory)pigmentsthatalsocontributetophotosynthesis.

Groupsofpigmentmoleculescalledantennacomplexesarepresentonthylakoids.

Lightstrikinganyoneofthepigmentmoleculesisfunneledtoaspecial

chlorophyllamolecule,termedareaction-centerchlorophyll,whichdirectly

participatesinphotosynthesis.Mostphotosyntheticorganismspossesstwotypes

ofreaction-centerchlorophylls,P680andP700,eachassociatedwithanelectron

acceptormoleculeandanelectrondonor.Theseaggregationsareknown

respectivelyasphotosystemI(P700)andphotosystemII(P680).

所有的光合作用生物含有不同等級的葉綠素和一個或多個類胡蘿卜素(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,每個光

系統(tǒng)都含有一個電子受體和電子供體。這些集合體就是大家熟識的光合系統(tǒng)I和光合系統(tǒng)

IIO

TheLight-DependentReaction：ConvertingSolarEnergyintoChemical-BondEnergy

光反應(yīng)：光能轉(zhuǎn)化成化學(xué)鍵能

Thephotosystemsofthelight-dependentreactionsareresponsibleforthe

packagingoflightenergyinthechemicalcompoundsATPandNADPH.This

packagingtakesplacethroughaseriesofoxidationreductionreactionssetin

motionwhenlightstrikestheP680reactioncenterinphotosystemII.Inthis

initialeventwatermoleculesarecleaved,oxygenisreleased,andelectronsare

donated.Theseelectronsareacceptedfirstbyplastoquinoneandthenbya

seriesofcarriersastheydescendanelectrontransportchain.Foreachfour

electronsthatpassdownthechain,twoATPsareformed.Thelastacceptorin

thechainistheP700reactioncenterofphotosystemI.Atthispointincoming

photonsboosttheenergyoftheelectrons,andtheyareacceptedbyferredoxin.

Ferredoxinisthenreoxidized,andthecoenzymeNADP+isreducedtotheNADPH.

TheATPgeneratedpreviouslyandtheNADPHthentakepartinthelight

independentreactions.

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NADPH。當(dāng)光激活光系統(tǒng)H的光反應(yīng)中心

時(shí)，通過一系列的氧化還原反應(yīng)實(shí)現(xiàn)能量的傳遞。反應(yīng)開始時(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，然后通過一系列載體形成的電子傳遞鏈。每傳遞4個電子，

形成2個ATP。最后一個受體存在于光反應(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NADPH。早期產(chǎn)生的ATP和

NADPH進(jìn)入暗反應(yīng)。

TheproductionofATPfromthetransportofelectronsexcitedbylightenergy-

downanelectrontransportchainistermedphotophosphorylation.Theone-way

flowofelectronsthroughphotosystemsIIandIiscallednoncyclic

photophosphorylation；plantsalsoderiveadditionalATPthroughcyclic

photophosphorylation,inwhichsomeelectronsareshuntedbackthroughthe

electrontransportchainbetweenphotosystemsIIandI.

8

由電子傳遞鏈偶連產(chǎn)生ATP的過程稱為光合磷酸化。通過光合系統(tǒng)n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n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,whicharedrivenbyATPand

NADPH,C02isconvertedtocarbohydrate.Thereactionsarealsoknownasthe

Calvin-Bensoncycle.AtmosphericC02,isfixedasitreactswithribulose

biphosphate(RuBP),areactionthatiscatalyzedbytheenzymeribulose

biphosphatecarboxylase.ThereductionOfC02tocarbohydrate(fructose

diphosphate)iscompletedviaseveralmorestepsofthecycle.Finally,RUBPis

regeneratedsothatthecyclemaycontinue.

由ATP和NADPH驅(qū)動的暗反應(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)

Highlevelsofoxygeninplantcellscandisruptphotosynthesisandcanalso

causephotorespiration-aninefficientfunofthedarkreactionsinwhich02is

fixedratherthanC02andnocarbohydrateisproduced.

ReprievefromPhotorespiration：TheC4Pathway

MostplantsareC3plants；theyexperiencedecreasedcarbohydrateproduction

underhot,dryconditionsasaresultoftheeffectsofphotorespiration.Among

C4plants,however,specialleafanatomyandauniquebiochemicalpathwayenable

theplanttothriveinandconditions.ThusC4plantslessenphotorespirationby-

carryingoutphotosynthesisonlyincellsthatareinsulatedfromhighlevelsof

C02.Theyalsopossessanovelmechanismforcarbonfixation.

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)一

Thefirststageinphotosynthesis,drivenbylightenergy.Electronsthattrap

thesun'senergypasstheenergytohigh-energycarrierssuchasATPorNADPH,

whereitisstoredinchemicalbonds,

light-independentreactions暗反應(yīng)

Thesecondstageofphotosynthesis,alsocalledtheCalvin-Bensoncycle,which

doesnotrequirelight.Duringthesixstepsofthecycle,carbonisfixedand

carbohydratesareformed,

chloroplast葉綠體

9

Aplastidinwhichphotosynthesisiscarriedout.Chloroplastsoccurinall

photosyntheticorganismsexceptphotosyntheticbacteriaandblue-greenalgae,

absorptionspectrum吸收光譜，吸收譜

Thespectrumobtainedwhenradiation(light,ultravioletradiation,etc.)froma

sourcegivingacontinuousspectrumispassedthroughasubstance.

Calvin-Bensoncycle卡爾文？本森循環(huán)

Cyclicreactionsthatarethe"synthesis"partofthelight-independentreactions

ofphotosynthesis.Inlandplants,RUBP,orsomeothercompoundtowhichcarbon

has

beenaffixed,undergoesrearrangementsthatleadtoformationofasugar

phosphateandtoregenerationoftheRUBP.ThecyclerunsonATPandNADPHfrom

light-dependentreactions,

carotenoid類胡蘿卜素

Light-sensitive,accessorypigmentsthattransferabsorbedenergyto

chlorophylls.Theyabsorbvioletandbluewave-lengthsbuttransmitred,orange,

andyellow,

chlorophyll葉綠素

Thegreensubstanceofplantsbywhichphotosynthesisisaccomplished；itis

usuallylocalizedinintracellularorganellescalledchloroplasts,

cyclicphotophosphorylation

環(huán)形光合磷酸化(作用)

Cyclicphotophosphorylationiscoupledtocyclicelectronflow,inwhichATPis

theonlyproduct.

C3plant三碳植物

Aplantinwhichthelight-independentreactionsofphotosynthesisstartwitha

threecarboncompound.MostplantsareC3plants.

C4plant四碳植物

Aplantsuchascorninwhichthelightindependentreactionsofphotosynthesis

starwithafour-carboncompound.

noncyclicphotophosphorylation

非環(huán)形光合磷酸化作用

Noncyclicphotophosphorylationiscoupledtononcyclicelectronflow,the

electronsbeingusedtoreduceNADP+aswellastomakeATP.

photon光子

Aparticlethathaszeromassorchargeandunitspin,thequantumofthe

electromagneticfieldandcarrieroftheelectromagneticforce,

photophosphorylation光合磷酸化作用

ThesynthesisofATPfromphosphateandADPduringphotosynthesis,usinglight

energy,

photorespiration光呼吸

Alight-dependenttypeofrespirationthatoccursinmostphotosyntheticplants

anddiffersfromnormal(ordark)respiration,

photosynthesis光合作用

10

Thesynthesisoforganiccompoundsbyreductionofcarbondioxideusinglight

energyabsorbedbychorophyll.

photosystem光合系統(tǒng)

Oneoftheclustersoflight-trappingpigmentsembeddedinphotosynthetic

membranes.PhotosystemIoperatesduringthecyclicpathway；photosystemII

operatesduringboththecyclicandnoncyclicpathways,ribulosebiphosphate

(RUBP)核酮糖二磷酸

Acompoundwithabackboneoffivecarbonatomsthatisrequiredforcarbon

fixationintheCalvin-Bensoncycleofphotosynthesis.

thylakoid類囊體

Oneofanumberofflattenedfluid-filledsacsthatformthephotosynthetic

lamellarsystemofchloroplasts,photosyntheticbacteria,andblue-greenalgae.

LessonThree(2學(xué)時(shí))

CellularReproduction：MitosisandMeiosis

教學(xué)目的：使學(xué)生掌握細(xì)胞的有絲分裂和無絲分裂的作用機(jī)理，有絲分裂和無絲分裂之間的

區(qū)別和相同點(diǎn)。相關(guān)英語詞匯以及主要用法。

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

教學(xué)難點(diǎn)：專業(yè)英語詞匯的記憶

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

授課時(shí)間：4月12日

教學(xué)內(nèi)容：

TheNucleusandChromosomes

Thecellnucleusisthemainrepositoryofgeneticinformation.Withinthe

nucleusarethechromosomestightlycoiledstrandsofDNAandclustersof

associatedproteins.LongstretchesofthecontinuousDNAmoleculewindaround

theseclustersofproteins,orhistones,formingbeadlikecomplexesknownas

nucleosomes.Morecoilingandsupercoilingproducesadensechromosomestructure.

EachlongstrandofDNAcombineswithhistonesandnonhistoneproteinstomakeup

thesubstancechromatin.

細(xì)胞核是貯藏遺傳信息的主要場所。DNA盤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)。每個長

鏈DNA與組蛋白和非組蛋白一起構(gòu)成染色質(zhì)物質(zhì)。

Apictorialdisplayofanorganism'schromosomesinthecoiled,condensedstate

isknownasakaryotype.Karyotyperevealthatinmostcellsallbutsex

chromosomesarepresentastwocopies,referredtoashomologouspairs.Non-sex

chromosomesarecalledautosomes.Organismswhosecellscontaintwosetsof

parentalchromosomesarecalleddiploid；thosewithcellscontainingasingleset

ofparentalchromosomesarecalledhaploid.

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

出現(xiàn)，稱同源染色體對。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,preparesfor

division,anddividestoformtwodaughtercells,eachofwhichthenrepeatsthe

cycle.Suchcyclingineffectmakessingle-celledorganismsimmortal.Many

cellsinmulticellularorganisms,includinganimalmuscleandnervecell