大学生物专业英语2

LessonTwoPhotosynthesisObject:1.Understandingthephotosynthesisconcept,substance,totalreactiontype,concreteprocessoflightanddarkreaction.2.Understandingrelationshipthatplantcultivationandreasonableutilizinglightenergythatmakeuseoftheknowledgeforphotosynthesisforlearning。absorptionspectrum吸收光谱Thespectrumobtainedwhenradiation(light,ultravioletradiatonetc)fromasourcegivingacontinuousspectrumispassedthroughasubstance.GlossaryCalvin-Bensoncycle卡尔文-本森循环ribulosebiphosphate（RuBP）orsomeothercompoundtowhichcarbonhasbeenaffixed,undergoesrearrangementsthatleadtoformationofasugarphosphateandtoregenerationoftheRuBP.ThecyclerunstoATPandNADPHfromlightindependentreactions.chlorophyll叶绿素Thegreensubtanceofplantsbywhichphotosynthesisisaccoomplished;itisusuallylocatedinintracellularorganenllescalledchloroplast.chloroplast叶绿体Aplstidinwhichphotosynthesisiscarriedout.Chloroplatstoccurinallphotosyntheticorganismsexceptphotosyntheticbacteriaandblue-greenalgae.cyclicphotophosphorylation环形光合磷酸化（作用）carotenoid类胡萝卜素Lightsensitive,accessorypigmentsthattransferabsorbedenergytochlorophylls.Theyabsorbvioletandbluewavelengthsbuttransmitred,orangeandyellow.一类重要的天然色素的总称。普遍存在于动物、高等植物、真菌、藻类和细菌中的黄色、橙红色或红色的色素，主要是β-胡萝卜素和γ-胡萝卜素，因此而得名。不溶于水，溶于脂肪和脂肪溶剂。thylakoid:类囊体oneofanumberofflattenedfluid-filledsacsthatformthephotosyntheticlamellarsystemofchloroplasts.Flattened:扁平的lamellar:片状eg:lamellarcrystal片晶/structure片层结构/process片状突起C3plantsC3植物是指在光合作用的暗反应过程中，一个CO2被一个五碳化合物(1，5-二磷酸核酮糖，简称RuBP)固定后形成两个三碳化合物(3-磷酸甘油酸)，即CO2被固定后最先形成的化合物中含有三个碳原子，所以称为C3植物。C4plants磷酸烯醇式丙酮酸，CO2同化的最初产物不是光合碳循环中的三碳化合物3-磷酸甘油酸，而是四碳化合物苹果酸或天门冬氨酸的植物。photorespiration光呼吸Alight-dependenttypeofrespirationthatoccursinmostphotosyntheticplantsanddiffersfromnormalrespiration.photophosphorylation光合磷酸化ThesynthesisofATPfromphosphateandADPduringphotosynthesis,usinglightenergy.photosystem光合系统Oneoftheclustersoflight-trappingpigmentsembeddedinphotosyntheticmembranes.PhotosystemΙoperatesduringthecyclicpathway;photosystemΠoperatesduringboththecyclicandnoncyclicpathways.Photosynthesischlorophyll-containingcells包含叶绿素的细胞convertslightenergyintochemicalenergy转化太阳能为化学能light-dependentreactionslight-independentreactionschloroplasts叶绿体thylakoidmembraneofchloroplastsstroma光反应暗反应叶绿体的类囊体膜上基质algae[´ældʒi:]藻类protist[´prəutist]原生生物bacteria[bæk´tiəriə]细菌respiration[respə´reiʃən]呼吸exergonic[eksə´ɡɔnik]放出能的endergonic[endə´ɡɔnik]需能的oxidize['ɔksi’daiz](使某物)氧化embedded[em´bedid]嵌入装入carbondioxide[dai´ɔksaid]CO2Photosynthesisoccursonlyinthechlorophyll-containingcellsofgreenplants,algae,andcertainprotistsandbacteria.Overall,itisaprocessthatconvertslightenergyintochemicalenergythatisstoredinthemolecularbonds.Fromthepointofviewofchemistryandenergetics,itistheoppositeofcellularrespiration.光合作用只发生在含有叶绿素的绿色植物细胞，海藻，某些原生动物和细菌之中。总体来说，这是一个将光能转化成化学能，并将能量贮存在分子键中，从化学和动能学角度来看，它是细胞呼吸作用的对立面。Whereascellularrespirationishighlyexergonicandreleasesenergy,photosynthesisrequiresenergyandishighlyendergonic.细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过程。PhotosynthesisstartswithCO2andH2Oasrawmaterialsandproceedsthroughtwosetsofpartialreactions.Inthefirstset,calledthelight-dependentreactions,watermoleculesaresplit(oxidized),02isreleased,andATPandNADPHareformed.Thesereactionsmusttakeplaceinthepresenceoflightenergy.光合作用以二氧化碳和水为原材料并经历两步化学反应。第一步，称光反应，水分子分解，氧分子释放，ATP和NADPH形成。此反应需要光能的存在。Inthesecondset,calledlight-independentreactions,CO2isreduced(viatheadditionofHatoms)tocarbohydrate.ThesechemicaleventsrelyontheelectroncarrierNADPHandATPgeneratedbythefirstsetofreactions.第二步，称暗反应，二氧化碳被还原成碳水化合物，这步反应依赖电子载体NADPH以及第一步反应产生的ATP。Bothsetsofreactionstakeplaceinchloroplasts.Mostoftheenzymesandpigmentsforthelightdependentreactionsareembeddedinthethylakoidmembraneofchloroplasts.Thedarkreactionstakeplaceinthestroma.两步反应都发生在叶绿体中。光反应需要的大部分酶和色素包埋在叶绿体的类囊体膜上。暗反应发生在基质中。光合细胞如何吸收光能的Theenergyinlightphotonsinthevisiblepartofthespectrumcanbecapturedbybiologicalmoleculestodoconstructivework.Thepigmentchlorophyllinplantcellsabsorbsphotonswithinaparticularabsorptionspectrumsstatementoftheamountoflightabsorbedbychlorophyllatdifferentwavelengths.生物分子能捕获可见光谱中的光能。植物细胞中叶绿素在不同光波下吸收部分吸收光谱。HowLightEnergyReachesPhotosyntheticCellsWhenlightisabsorbeditaltersthearrangementofelectronsintheabsorbingmolecule.Theaddedenergyofthephotonbooststheenergyconditionofthemoleculefromastablestatetoaless-stableexcitedstate.Duringthelight-dependentreactionsofphotosynthesis,astheabsorbingmoleculereturnstothegroundstate,theexcessexcitationenergyistransmittedtoothermoleculesandstoredaschemicalenergy.在吸收分子中，光的作用使分子中的电子发生重排。光子的能量激活了分子的能量状态，使其从稳定态进入不稳定的激活态。Allphotosyntheticorganismscontainvariousclassesofchlorophyllsandoneormorecarotenoid(accessory)pigmentsthatalsocontributetophotosynthesis.Groupsofpigmentmoleculescalledantennacomplexesarepresentonthylakoids.所有的光合作用生物含有不同等级的叶绿素和一个或多个类胡萝卜素（光合作用的辅助色素）。称作天线复合体的色素分子群存在于类囊体中。antennapigment（天线色素，聚光色素light-harvesting）指在光合作用中起吸收和传递光能作用的色素分子，他们本身没有光化学活性。Mostphotosyntheticorganismspossesstwotypesofreaction-centerchlorophylls,P680andP700,eachassociatedwithanelectronacceptormol