SATII生物部分资料附翻译

TheMoleculesofLifeTheelementsinvolvedinlifeprocessescan,anddo,formmillionsofdifferentcompounds.Thankfully,thesemillionsofcompoundsfallintofourmajorgroups:carbohydrates,proteins,lipids,andnucleicacids.Thoughallofthesegroupsareorganizedaroundcarbon,eachgrouphasitsownspecialstructureandfunction.分子的生活脂类，核酸.全部这些四周都是由碳的构造组成，每组hasits？拥有特别的构造和功能。CarbohydratesCarbohydratesarecompoundsthathavecarbon,hydrogen,andoxygenatomsinaratioofabout1:2:1.Ifyou’restuckonanSATIIBiologyquestionaboutwhetheracompoundisacarbohydrate,justcountuptheatomsandseeiftheyfitthis ratio.Carbohydrates are often sugars, which provide energy forcellularprocesses.Likeallofthebiologicallyimportantclassesofcompounds,carbohydratescanbemonomers,dimers,orpolymers.Thenamesofmostcarbohydratesendin“-ose”:glucose,fructose,sucrose,andmaltosearesomecommonexamples.碳水化合物1：2：1。假设在SAT2生物学考比。碳水化合物往往是供给能源给细胞的过程的糖类。像全部的生物重要化合物的种类如：碳水化合物，单体，二聚体，或者聚合体。大局部碳水化合物名字的后面有“-OSE”：葡萄糖，果糖，蔗糖，麦芽糖是一些常见的例子。MonosaccharidesCarbohydratemonomersareknownasmonosaccharides.Thisgroupincludesglucose,C6H12O6,whichisakeysubstanceinbiochemistry.Sugarsthatananimaleatsareconvertedintoglucose,whichisthenconvertedintoenergytofueltheanimal’sactivitiesbyrespiration(s eeCellProcesses).Glucosehasacousincalledfructosewiththesamechemicalformula.Butthesetwocompoundshavedifferentstructures:Glucose and fructose differ in one importantway: glucose has adouble-bondedoxygenonthetopcarbon,whilefructosehasitsdouble-bondedcarbononthesecondcarbon.Thisdifferenceismostapparentwhenthetwomonosaccharidesareintheirringforms.Glucosegenerallyformsahexagonalring(sixsided),whilefructoseformsapentagonalring(fivesided).Whereasfructoseisthesugarmostoftenfoundinfruits,glucoseismostoftenusedasthemajorsourceofenergyforcellularactivities.单糖碳水化合物单体被称为单糖。单糖包括葡萄糖，酒精，这是生物化学中一个关键呼吸作用消耗的能量。葡萄糖与果糖具有一样的化学分子〔C6H1206)但是这两个化合物具有不同的构造(我没记错的话是一个有醛基，一个没有〕〔6片面〕，而果糖形成了一个五角环〔5片面〕。在水果中的经常发下的糖是果糖，葡萄糖是作为主要的能源来源，为细胞活动供给能量。DisaccharidesDisaccharidesarecarbohydratedimers.Thesedimersareformedfromtwomonomers by dehydrationsynthesis. Any two monosaccharides can form adisaccharide.Forexample,maltoseisformedbythedehydrationsynthesisoftwoglucosemolecules.Sucrose,commontablesugar,comesfromthelinkageofonemoleculeofglucoseandoneoffructose.二糖来说，麦芽糖是由脱水合成二葡萄糖分子。蔗糖，淀粉，是由葡萄糖和果糖组成的。PolysaccharidesPolysaccharidescanconsistofasfewasthreeandasmanyasseveralthousandmonosaccharides.Dependingontheirstructureandthemonosaccharidestheycontain,polysaccharidescanfunctionasameansofstoringexcessenergyorprovidestructuralsupport.Whencellsingestmorecarbohydratesthantheyneedforfuel,theylinkthesugarstogethertoformpolysaccharides.Thestructureofthesepolysaccharidesisdifferentinplantsandanimals:inplants,polysaccharidestaketheformofstarch,whereasinanimals,theyarelinkedinastructurecalledglycogen.Polysaccharidescanalsohavestructuralrolesinplantsandanimals.Cellulose,whichformsthecellwallsofplantcells,isastructuralpolysaccharide.Inanimals,thepolysaccharidechitinformsthehardouterarmorofinsects,crabs,spiders,andotherarthropods.Manyfungialsousechitinasastructuralcarbohydrate.多糖以多糖可以储存过剩的能源或供给构造性支持。构，植物和动物的多糖不一样：在植物中，多糖存在形式是淀粉，而在动物，他们链接一起后存在形式是糖元。维素就是是一个构造性的多糖。在动物方面，多糖甲壳素形式铠甲如昆虫，螃蟹，蜘蛛，和其他节肢动物的壳。很多真菌也利用甲壳素作为一个构造性碳水化合物。ProteinsMorethanhalfoftheorganiccompoundsincellsareproteins,whichplayanimportantfunctioninalmosteverycellularprocess.Proteins,forexample,providestructuralsupporttothecellinthecytoskeletonandmakeupmanyofthehormonesthatsendmessagesaroundthebody.Enzymes,whichregulatechemicalreactionsinthecell,arealsoproteins.蛋白质的骨架和输送激素到身体的各个部位。在细胞中酶调整化学反响，也是靠蛋白质〔由于酶就是一种蛋白质〕AminoAcidsProteinsaremadeupofmonomerscalledaminoacids.Thenamesofmany,butnotall,aminoacidsendin-ine:methionine,lysine,serine,etc.Eachaminoacidconsistsofacentralcarbonatomattachedtoasetofthreedesignatedgroups:anatomofhydrogen(–H),anaminogroup( –NH2),andacarboxylgroup( –COOH).Thefinalgroup,designated( –R)inthediagrambelow,variesbetweendifferentaminoacids.ItispossibletomakeaninfinitenumberofaminoacidsbyattachingdifferentcompoundstotheRpositionofthecentralcarbon.However,only20typesofRgroupsexistinnature,sothereareonly20naturallyoccurringaminoacids.氨基酸氨基酸是蛋白质的单体。他的名称很多，都以INE结尾：蛋氨酸，赖氨酸，丝氨酸等，每个氨基酸组成的中心碳原子上都连有3个基团这是不会变的：1原子氢〔-H〕的，一氨基酸组〔-NH2〕，和一个羧基〔-COOH〕。最终一组，都是R基〔-R〕在如以下图，R这也就是说可以有很多种的氨基酸，只要中心碳的支链上有不同的R基。但是，在性质上只有20R20种氨基酸。多肽这20个氨基酸的局部或全部制成全部的蛋白质的链-NH2与-OH之间称作一个肽键2个集团组合到一起的过程就叫脱水缩合氨基酸为其主要构造，某一特定蛋白质有特定的氨基酸序列，这是众所周知。每一个蛋白质在三维立体空间中经过一系列的过程如卷等这些都是都预定好的的2级〔初步绕组和卷取〕和三级构造〔整体折叠〕。在苛刻的条件，如高温或极端的pH性”。PolypeptidesAllproteinsaremadeofchainsofsomeorallofthese20aminoacids.Thebondformedbetweentwoaminoacidsbydehydrationsynthesisisknownasapeptidebond.Aparticularproteinhasaspecificsequenceofaminoacids,whichisknownasitsprimarystructure.Everyproteinalsowinds,coils,andfoldsinthree-dimensionalspaceinspecificandpredeterminedways,takingonauniquesecondary(initialwindingandcoiling)andtertiarystructure(overallfolding).Inharshconditions,suchashightemperatureorextremepH,proteinscanlosetheirnormaltertiaryshapeandceasetofunctionproperly.Whenaproteinunfoldsinharshconditions,ithasbeen“denatured.”血脂相连。这种链不溶于水，由于他们非极性。甘油三酯甘油三酸酯的构成为三条长链烃末端连有不饱和脂肪酸，叫做甘油。由于他们包括3个脂肪酸，脂肪油砂也被称为甘油三酯。由于这点，甘油和脂肪酸，相互进入对方脱水的合成。肪酸的油脂。饱和脂肪没有碳碳双键，不饱和脂肪酸，而包含一个或多个这样碳碳双键。在和脂肪通常是液体。LipidsLipidsarecarboncompoundsthatdonotdiss