生物物理所蛋白质平台Titan Krios安装工程监理第7次会议纪要

某大学生物工程学院《普通生物化学》课程试卷（含答案）__________学年第___学期考试类型：（闭卷）考试考试时间：90 分钟年级专业_____________学号_____________ 姓名_____________1、判断题（140分，每题5分）1. 热休克蛋白是分子伴侣。

（）[中国科学技术大学2008研]答案：正确解析：2. 二硝基苯酚和寡霉素均能抑制线粒体的氧化磷酸化作用，但在二硝基苯酚的存在下加入寡霉素，则对电子传递过程并不发生影响。

（）[山东大学2016研]答案：正确解析：寡霉素阻断质子通过ATP合酶的通道，使ATP的合成受阻，由于质子泵出线粒体需要更高的能障，电子传递被抑制，氧的消耗停止。

二硝基苯酚存在时，ATP的合成仍然因为寡霉素的存在而被抑制，但质子梯度被二硝基苯酚破坏，所以消除了寡霉素对电子传递的抑制，所以电子传递过程能够继续进行。

3. 酶在细胞内的半寿期主要取决于它的降解速率而不是合成速率。

（）答案：正确解析：4. 锌指蛋白与锌的结合必须有DNA的存在。

（）答案：错误解析：不需要DNA的存在，是通过保守的半胱氨酸和组氨酸残基间协调进行的。

5. 各种物质甲基化修饰的甲基直接来源于N5甲基四氢叶酸。

（）答案：错误解析：6. 蛋白质的营养价值主要取决于必需氨基酸的种类、含量和比例。

（）答案：正确7. 线粒体内膜ADPATP载体蛋白在促进ADP由细胞质进入完整线粒体基质的同时ATP由完整线粒体基质进入细胞质的过程是需要能量的。

（）答案：正确解析：因为此过程的完成需要通过呼吸作用形成跨线粒体膜的电位（内负，外正）驱动运输蛋白的运输作用。

8. CTP参加磷脂生物合成，UTP参加糖原生物合成，GTP参加蛋白质生物合成。

（）答案：正确解析：CTP是一种核苷酸，为高能分子，是成RNA的原料之一，可参与甘油磷脂的合成，UTP参加糖原生物合成，是糖基的供体，蛋白质肽链的延伸需要GTP供能。

letters to nature8.Leznoff,C.C.&Lever,A.B.P.(eds)Phthalocyanines:Properties and Applications(VCH,New York,1989).9.Wang,L.S.,Ding,C.F.,Wang,X.B.&Barlow,S.E.Photodetachment photoelectron spectroscopy ofmultiply charged anions using electrospray ionization.Rev.Sci.Instrum.70,1957±1966(1999). 10.Berkowitz,J.Photoelectron spectroscopy of phthalocyanine vapors.J.Chem.Phys.70,2819±2828(1979).11.Brown,C.J.Crystal structure of b-copper phthalocyanine.J.Chem.Soc.A2488±2493(1968).12.Rosa,A.&Baerends,E.J.Metal-macrocycle interaction in phthalocyanines:density functionalcalculations of ground and excited states.Inorg.Chem.33,584±595(1994).13.PC Spartan Plus5.1(Wavefunction,Inc.,Von Carman Ave.,Irvine,California92612,USA).14.Stewart,J.J.Optimization of parameters for semiempirical methods II:put.Chem.10;221±264(1989);MOPAC:A semiempirical molecular orbital put.Aided Mol.Design4;1±105(1990).15.D'Haennens,I.J.in Encyclopedia of Physics(eds Lerner,R.G.&Trigg,G.L.)1251±1253(VCH,NewYork,1991).16.Hodgson,P.E.,Gadioli,E.&Erba,E.G.Introductory Nuclear Physics(Clarendon,Oxford,1997).17.Scheller,M.K.&Cederbaum,L.S.A construction principle for stable multiply charged molecularanions in the gas phase.Chem.Phys.Lett.216,141±146(1993).18.Weikert,H.-G.&Cederbaum,L.S.Free doubly negative tetrahalides.J.Chem.Phys.99,8877±8891(1993).19.Boldyrev,A.I.,Gutowski,M.&Simons,J.Small multiply charged anions as building blocks inchemistry.Acc.Chem.Res.29,497±502(1996).20.Vekey,K.Multiply charged ions.Mass Spectrom.Rev.14,195±225(1995).21.Brechignac,C.,Cahuzac,P.,Kebaili,N.&Leygnier,J.Temperature effects in the Coulombic®ssion ofstrontium clusters.Phys.Rev.Lett.81,4612±4615(1998).22.Schroder,D.,Harvey,J.N.&Schwarz,H.Long-lived,multiply charged diatomic TiF n+ions(n=1±3).J.Phys.Chem.A102,3639±3642(1998).Acknowledgements.We thank R.S.Disselkamp for discussions and K.Ferris for help in the theoretical calculations.This work was supported by the US Department of Energy,Of®ce of Basic Energy Sciences, Chemical Sciences Division and is conducted at the Paci®c Northwest National Laboratory,operated for the US Department of Energy by Battelle Memorial Institute.L.-S.W.is an Alfred P.Sloan research fellow.Correspondence and requests for materials should be addressed to L.-S.W.(e-mail:ls.wang@).Dual modes of thecarbon cycle since theLast Glacial MaximumH.Jesse Smith*,H.Fischer*²,M.Wahlen*,D.Mastroianni* &B.Deck**Scripps Institution of Oceanography,University of California San Diego,La Jolla,California92093-0220,USA ......................................................................................................................... The most conspicuous feature of the record of past climate contained in polar ice is the rapid warming which occurs after long intervals of gradual cooling.During the last four transitions from glacial to interglacial conditions,over which such abrupt warmings occur,ice records indicate that the CO2concentration of the atmosphere increased by roughly80to100parts per million by volume(refs1±4).But the causes of the atmospheric CO2 concentration increases are unclear.Here we present the stable-carbon-isotope composition(d13CO2)of CO2extracted from air trapped in ice at Taylor Dome,Antarctica,from the Last Glacial Maximum to the onset of Holocene times.The global carbon cycle is shown to have operated in two distinct primary modes on the timescale of thousands of years,one when climate was changing relatively slowly and another when warming was rapid,each with a characteristic average stable-carbon-isotope composition of the net CO2exchanged by the atmosphere with the land and oceans. d13CO2increased between16.5and9thousand years ago by slightly more than would be estimated to be caused by the physical effects of a58C rise in global average sea surface temperature driving a CO2ef¯ux from the ocean,but our data do not allow speci®c causes to be constrained.Carbon dioxide in the atmosphere causes a radiative forcing second only to water vapour,and so may be a central agent in climate change.Polar ice cores contain a detailed record of climate-²Present address:Alfred-Wegener-Institute for Polar and Marine Research,Columbusstrasss,D-27515 Bremerhaven,Germany.related variables which extends more than400,000years into the past4,and are especially valuable for studying variations of atmos-pheric CO2as they contain an effectively direct record,unlike atmospheric proxies such as marine carbonates or preserved organic material5which may also re¯ect biological effects.Ice cores from Antarctica,such as those of Taylor Dome and Vostok, are the best sources for palaeoatmospheric CO2measurements because they contain only small amounts of the kinds of chemical impurities,such as carbonate dust or organic acids,that may lead to contamination by in situ CO2production2,6±8.Taylor Dome ice has the additional advantage that the entire554-m-long core is from above the depth at which air trapped in bubbles in the ice forms gas±ice clathrates.This feature is important because,as we have found,the accuracy of d13CO2measurements performed on bubble-free ice may be affected by the presence of clathrates.(d13C is de®ned in Methods.)We have measured the CO2concentration and d13CO2 of air trapped in ice from Taylor Dome,Antarctica,across the last glacial termination in order to develop a time series for the carbon-isotope composition of atmospheric CO2and to constrain the mechanisms of carbon cycling between the main sources and sinks of atmospheric CO2.The atmospheric CO2concentration data3,9(Fig.1)form a record comparable to that from Byrd and Vostok1,2.The salient features include a low but variable concentration of atmospheric CO2 between27.1and18.0kyr BP(thousand years before present, where``present''is de®ned as AD1950),when it varied between 186and201parts per million by volume(p.p.m.v.);a rise,at a fairly constant rate,from190p.p.m.v.at17.0kyr BP to an early Holocene local maximum of268p.p.m.v.at10.6kyr BP,punctuated by a shallow minimum at16.1kyr BP and a drop of8p.p.m.v.between 14and13kyr BP which may be related to the Antarctic Cold Reversal3;an8p.p.m.v.decrease,from268p.p.m.v.at10.6kyr BP to260p.p.m.v.at9.1kyr BP,followed by a rise to the pre-industrial level of about280p.p.m.v.(as discussed in detail by IndermuÈhle et al.9).These data can be combined with the carbon-isotope composition of the CO2to give a better picture of how the carbon cycle operated during this time.The main features of the carbon-isotope record shown in Fig.1 include a0.5½drop in d13CO2between18.0and16.5kyr BP,and the subsequent increase of0.7½,from-7.0½to-6.3½, between16.5and9.1kyr BP,which is interrupted by two local d13CO2minima at approximately13and10kyr BP.The minimum-to-maximum d13CO2increase began1,000to2,000years after CO2began to rise,and continued to rise for,3,000years after the CO2concentration maximum at10.6kyr BP,which we interpret as a consequence of the bimodality of carbon cycling(discussed below)rather than a decoupling of CO2concentrations from carbon-isotope compositions.Furthermore,there appears to have been an extended local minimum in d13CO2between13.4and 12.3kyr BP that accompanied the Younger Dryas10but was not concurrent with the CO2concentration drop at14kyr BP.The 0.16½difference between the average d13CO2values of the Last Glacial Maximum(LGM)and Holocene(see Fig.2legend for an explanation of these groupings)is similar to the increase of 0:1960:18½estimated by Leuenberger et al.11to have occurred between the period20±40kyr BP and the early Holocene.These data show,however,that there was a signi®cant drop in d13CO2 between the end of the LGM and the beginning of the transition, and that the subsequent rise into the early Holocene was much larger than the difference between average values for the LGM and Holocene.Moreover,inferences about the carbon cycle drawn from the comparison of the LGM and Holocene averages may be misleading because there was signi®cant variability within each of those periods,and the averages depend strongly on the interval chosen to calculate them.Finally,the variability of d13CO2before17.5kyr BP and after10.3kyr BP,0.33½and 0.37½,respectively,is about half of the magnitude of theletters to natureincrease that occurs during the transition,indicating that carbon cycling also varied considerably over shorter timescales.The atmospheric portion of the carbon cycle is extremely dynamic;,20%of the CO 2in the atmosphere is exchanged with the ocean and terrestrial biosphere every year (ref.12),so the atmosphere responds very quickly to changes in CO 2cycling between these three reservoirs.The exchange of carbon can affect the isotopic composition of atmospheric CO 2for two reasons.First,the reservoirs have different carbon-isotope compositions (the d 13CO 2of the ocean is close to 0½,the terrestrial biosphere has a d 13CO 2of approximately -25½and that of pre-industrial atmos-phere was approximately -6.5½;ref.13).Second,each ¯ux of CO 2between the atmosphere and either the ocean or the terrestrial biosphere is accompanied by a different carbon-isotope fractiona-tion,resulting in isotopically unique values of d 13CO 2for each transfer.Consequently,variations in the carbon-isotope composi-tion of atmospheric CO 2can be caused by a net ¯ux of carbon between reservoirs,or by a change in the isotopic fractionation associated with a particular atmospheric ¯ux.It also follows from this that the carbon-isotope composition of the net atmospheric CO 2exchanged,d 13CO 2(ex),is a function of the relative strengths of processes which transfer CO 2into and out of the atmosphere,so different d 13CO 2(ex)values indicate different balances of processes.When a unique balance of processes persists over thousands of years,as indicated by a unique d 13CO 2(ex),we refer to it as a `mode'of the carbon cycle.In order to examine more closely the implications of the time series shown in Fig.1,it is advantageous to consider the three data groups (LGM,transition and Holocene)individually.Doing so inFig.2reveals a relationship between the concentration of atmos-pheric CO 2and its carbon-isotope composition during each of these intervals.(Figure 2is a mixing diagram,where the inverse CO 2concentration is plotted against d 13CO 2,so that addition or removal of CO 2with a given d 13C would appear as a nearly straight line with the y -intercept approximately equal to the isotopic composition of the net CO 2added to,or subtracted from,the atmosphere.)The coherent trends displayed by these groups show that the carbon cycle has operated in two distinct modes over the past 27kyr,one during the Holocene,and possibly the LGM as well,when the average d 13C of net CO 2exchanged was approximately -10½,and another during the transition,when the average d 13C of net CO 2exchanged was approximately -5½.In other words,during the period of relatively stable,slowly changing climate of the Holocene,the carbon of the net exchanged atmospheric CO 2was isotopically lighter than the average atmospheric value (that is,d d 13CO 2/dCO 2was negative).In contrast,during the period of rapidly changing climate of the transition the net exchanged CO 2was isotopically heavier (d d 13CO 2/dCO 2was positive).Therefore,these data suggest that the carbon cycle has operated in two primary modes over the past 27kyr,one when climate is changing only slowly and another when rapid warming occurs,and that although there are clearly other processes which have affected atmospheric CO 2over the past 27kyr,as is evident from the scatter in the data shown in Fig.2,those transient variations did not overwhelm the longer-term trends.Many schemes have been advanced to account for the magnitude of the rise in the concentration of atmospheric CO 2during deglaciations (see,for example,Broecker 14for a critical review),although none seem to be uniquely suf®cient.Two factors which must be included in any analysis of the glacial±interglacial increase in atmospheric CO 2content,however,are a rise in sea surface temperature (SST)and a decrease in ocean salinity (S).In the range of SST,atmospheric CO 2concentration and salinity appropriate for this study,changes in SST affect both atmospheric p CO 2and d 13CO 2,by approximately 4.2%per 8C (ref.15)and 0.11±0.13½per 8C (ref.16),respectively,while changes in salinity alter p CO 2by 10p.p.m.v.per ½S without affecting its d 13C (ref.17).Measurements per-formed on tropical corals show that SST increased by 5±68CfromFigure 1d 13CO 2and CO 2-concentration trends.The data are based on measurements of air trapped in ice from Taylor Dome,Antarctica,and are plotted against air age.Upper curve,d 13CO 2values (®lled circles)within envelopes of 1j and 2j uncertainty (indicated as dotted and solid lines,respectively;see the Methods section for details).Lower curve,CO 2concentration data shown as open circles were measured in our laboratory at SIO 3,while the solid line shown in the Holocene (for comparison)is the higher-resolution record of Indermu hle et al.9.The age axis is divided into three intervals,called ``LGM'',``transition'',and ``Holocene''on the basis of CO 2concentrations and generally accepted ages for these periods.The LGM group includes all of the points with air ages between 27.1and 18.0kyr BP ,the youngest being the last with a CO 2concentration below the highest value of the older samples.The transition group includes the points with ages between 17.0and 10.6kyr BP ,where the local CO 2maximum which we use to de®ne the start of the Holocene occurs.The Holocene group includes all the points with ages between 10.1and 1.3kyr BP (the youngest sample measured for d 13CO 2).The boundaries between the LGM and the transition,and between the transition and the Holocene,chosen here to fall at 17.5and 10.3kyr BP ,respectively,are shown as vertical dashedlines.[CO 2] (p.p.m.)1/[CO 2] (p.p.m.-1)δ13C O 2 (‰)Figure 2Mixing diagram for Taylor Dome samples:1/[CO 2]is plotted against d 13CO 2.The data are divided into three groups,as described in the ®gure:the LGM group (open triangles,6d 13CO 2points),the transition group (®lled circles,15d 13CO 2points),and the Holocene group (open squares,10d 13CO 2points).The y -intercept of the regression line through each of the three groups of data,along with the corresponding 1j uncertainty for each value,indicates the d 13C of the CO 2exchanged by the atmosphere,d 13CO 2(ex),and is shown on the ®gure.letters to naturethe last peak-glacial period to the early Holocene18,signi®cantly more than the earlier estimate of1±28C by CLIMAP19,while the change in ocean salinity,estimated from sea level change20,was approximately-1.4½.Assuming a global average D SST(sea surface temperature change)of58C,the combined effects of temperature and salinity changes should have resulted in increases in the concentration and d13CO2of roughly30p.p.m.v.and0.6½, respectively.If this were true,then all other processes which caused variations in atmospheric CO2must together have increased its concentration by,50p.p.m.v.and its d13CO2by only0.1½.A 28C global average D SST,on the other hand,would have caused no signi®cant change in the concentration of atmospheric CO2and increased d13CO2by roughly0.2½,leaving unexplained an approximately80p.p.m.concentration increase and a0.5½d13CO2increase.Adding these changes to the0.3½whole-ocean d13CO2increase which is thought to have accompanied deglaciation21,the expected increase in atmospheric d13CO2would be between0.9½and0.6½,depending on whether a D SST of5or 28C is assumed.The observed increase of0.7½would seem to imply,then,that it is not necessary to invoke a large decrease in surface ocean productivity(which would lower atmospheric d13CO2 to values more negative than are observed)to explain the d13CO2 increase during the transition.What does become necessary,then,is to explain the0.5½drop seen between18and16.5kyr BP.In the broadest sense,the atmospheric d13CO2record presented here points to the ocean as the predominant source of atmospheric CO2during the transition.This interpretation follows from two observations.First,even if a change in average global SST alone had caused the increase in d13CO2,a realistic D SST would have resulted in an increase of atmospheric CO2concentration of less than half of what is observed,so there must have been other sources of CO2 during that time.Second,because d13CO2was increasing at a rate equal to or greater than that which rising SST alone would have caused,the additional net CO2¯ux must have had a d13CO2equal to, or greater than,that of the coexisting atmosphere,eliminating the terrestrial biosphere as a possible source.The most likely explana-tion for this is an enhanced¯ux from the ocean(with a d13C close to that of the atmosphere)which transferred CO2into the atmosphere at a rate greater than the concurrent uptake of isotopically light CO2 by an expanding terrestrial biosphere.Unfortunately,the con-straints imposed by these data are insuf®cient to allow the identi-®cation of a speci®c cause for the increased¯ux of CO2from the ocean to the atmosphere.A better understanding of the carbon cycle depends not only on better models,but on additional experimental constraints on the carbon system,particularly more precise data about changes in SST,the size and composition of the terrestrial biosphere,the growth of coral reefs during periods of sea level rise, marine productivity and the chemical composition of the oceans.M ......................................................................................................................... MethodsAll samples were taken from Taylor Dome,Antarctica(7708489S,1588439E, elevation2,374m),drilled in1993/94.The methods used for determining the CO2concentration of air trapped in ice and the measurement of its carbon-isotope composition are described in detail elsewhere22,23.CO2concentration measurements have an internal precision of63p.p.m.v.(2j)and are calculated by comparison to three standards of precisely known compositions which are run with every sample.The Craig-corrected24carbon-isotope measurements, performed on our VG Prism II isotope ratio mass spectrometer,have a1j precision of60.075½,based on numerous analyses of the CO2separated from an atmospheric air standard exposed to uncrushed ice,in order to simulate the conditions of a sample run and to check for fractionation during extraction. d13CO2is reported in normal d notation as the per mil difference between the isotopic composition of the sample and standard VPDB carbon, 13C=12C sample= 13C=12C VPDB21 31;000 .The d13CO2values reported here have been corrected for the gravitational separation of gases of different masses in the®rn,and for the presence of N2O (which results in isobaric interferences with CO2during mass spectrometry).Gravitational separation in the®rn25,26was determined by using the values of d15N2of air trapped in Taylor Dome ice from Sucher27,following the approach of Sowers and Bender28.The gravitational correction for d13CO2is,0.005½per m.C-isotope data are corrected for the presence of N2O on the basis of calibrations performed in our laboratory on CO2±N2O mixtures.The N2O concentrations of atmospheric air used for this correction,adapted from Leuenberger and Siegenthaler29,are linear interpolations of the following concentrations and dates:275p.p.b.(0±9.25yr BP),200p.p.b.(16.1±27.2kyr BP).The N2O correction is,0.001½per p.p.b.of N2O.The total1j uncertainty in the reported d13CO2of a single sample,including uncertainties in the gravitational and N2O corrections,is0.085½.Duplicate analyses of samples with air ages of2.19and17.2kyr BP have a1j uncertainty of0.060½and a triplicate analysis of the sample with an air age of27.4kyr BP has a1j uncertainty of0.049½.The depth±age scale and air age±ice age differences were calculated using a combination of¯ow modelling,correlating variations in the d18O of the ice with the well-dated GISP2,and matching atmospheric CH4concentrations and d18O of O2with variations seen in GISP230.Received8October1998;accepted7June1999.1.Barnola,J.M.,Raynaud,D.,Korotkevich,Y.S.&Lorius,C.Vostok ice core provides160,000-yearrecord of atmospheric CO2.Nature329,408±414(1987).2.Neftel,A.,Oeschger,H.,Staffelbach,T.&Stauffer,B.CO2record in the Byrd ice core50,000±5,000years BP.Nature331,609±611(1988).3.Fischer,H.,Wahlen,M.,Smith,H.J.,Mastroianni,D.&Deck,B.Ice core records of atmospheric CO2around the last three glacial terminations.Science283,1712±1714(1999).4.Petit,J.R.et al.Climate and atmospheric history of the past420,000years from the Vostok ice core,Antarctica.Nature399,429±436(1999).5.Marino,B.,McElroy,M.B.,Salawitch,R.J.&Spaulding,W.G.Glacial-to-interglacial variations in thecarbon isotopic composition of atmospheric CO2.Nature357,461±466(1992).6.Anklin,M.,Barnola,J.-M.,Schwander,J.,Stauffer,B.&Raynaud,D.Processes affecting the CO2concentrations measured in Greenland ice.Tellus B47,461±470(1995).7.Delmas,R.J.A natural artefact in Greenland ice core CO2measurements.Tellus B45,391±396(1993).8.Barnola,J.M.et al.CO2evolution during the last millennium as recorded by Antarctic and Greenlandice.Tellus B47,264±272(1995).9.IndermuÈhle,A.et al.Holocene carbon-cycle dynamics based on CO2trapped in ice at Taylor Dome,Antarctica.Nature398,121±126(1999).10.Fairbanks,R.G.The age and origin of the``Younger Dryas Climate Event''in Greenland ice cores.Paleoceanography5,937±948(1990).11.Leuenberger,M.,Siegenthaler,U.&Langway,C.C.Carbon isotope composition of atmospheric CO2during the last ice age from an Antarctic ice core.Nature357,488±490(1992).12.Tans,P.P.,Berry,J.A.&Keeling,R.F.Oceanic13C/12C observations:a new window on ocean CO2uptake.Glob.Biogeochem.Cycles7,353±368(1993).13.Friedli,H.,Lotscher,H.,Oeschger,H.,Siegenthaler,U.&Stauffer,B.Ice core record of the13C/12C ofatmospheric CO2in the past two centuries.Nature324,237±238(1986).14.Broecker,W.S.&Henderson,G.M.The sequence of events surrounding T ermination II and theirimplications for the cause of glacial-interglacial CO2changes.Paleoceanography13,352±364(1998).15.Takahashi,T.,Olafsson,J.,Goddard,J.G.,Chipman,D.W.&Sutherland,S.C.Seasonal variation ofCO2and nutrients in the high-latitude surface oceans:a comparative study.Glob.Biogeochem.Cycles 7,843±878(1993).16.Mook,W.G.,Bommerson,J.C.&Staverman,W.H.Carbon isotope fractionation between dissolvedbicarbonate and gaseous carbon dioxide.Earth Planet.Sci.Lett.22,169±176(1974).17.Weiss,R.F.Carbon dioxide in water and seawater:the solubility of a non-ideal 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transition.Geophys.Res.Lett.24,1±4(1997).24.Craig,H.Isotopic standards for carbon and oxygen and correction factors for mass-spectrometricanalysis of carbon dioxide.Geochim.Cosmochim.Acta12,133±149(1957).25.Craig,H.,Horibe,Y.&Sowers,T.Gravitational separation of gases and isotopes in polar ice caps.Science242,1675±1678(1988).26.Schwander,J.The Environmental Record in Glaciers and Ice Sheets(eds Oeschger,H.and Langway,C.C.)53±67(Wiley and Sons,New York,1989).27.Sucher,C.Trapped Gases in the Taylor Dome Ice Core:Implications for East Antarctic Climate Change.Thesis,Univ.Rhode Island(1997).28.Sowers,T.&Bender,M.Elemental and isotopic composition of occluded O2and N2in polar ice.J.Geophys.Res.94,5137±5150(1989).29.Leuenberger,M.&Siegenthaler,U.Ice-age atmospheric concentration of nitrous oxide from anAntarctic ice core.Nature360,449±451(1988).30.Steig,E.J.et al.Synchronous climate changes in Antarctica and the North Atlantic.Science282,92±95(1998).Acknowledgements.We thank G.Hargreaves and 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第一章1、概念：分子生物学DNA重组技术结构分子生物学“基因”的分子生物学定义：产生一条功能多肽链或功能RNA所必需的全部核甘酸序列。

2、用你现有的知识解释DNA为什么是遗传信息的载体。

3、关注了解近几年诺贝尔奖获得者及其科学发现。

第二章名词解释:DNA的C值：C值是一种生物的单倍体基因组DNA的总量。

C值矛盾（C Value paradox）：C值一般随生物进化而增加，研究发现某些两栖类的C值甚至比哺乳动物还大，而在两栖类中C值变化也很大，这种C值与生物进化（结构和组织的复杂性）矛盾的现象称为C值矛盾。

冈崎片段DNA的半保留复制（semi-conservative replication）：由亲代DNA生成子代DNA时，每个新形成的子代DNA中，一条链来自亲代DNA，而另一条链则是新合成的，这种复制方式称半保留复制。

半不连续复制（semi-conservative replication）：DNA复制时其中一条子链的合成是连续的，而另一条子链的合成是不连续的，故称半不连续复制。

复制子(Replicon)：从复制原点到终点，组成一个复制单位，叫复制子。

转座子（transposon）：存在于染色体DNA上可自主复制和位移的基本单位。

反转录转座子（retrotransposon）：指通过RNA为中介，反转录成DNA后进行转座的可动元件。

单链结合蛋白(SSBP-single-strand binding protein)：在DNA复制过程中，稳定已被解开的DNA单链，阻止复性和保护单链不被核酸酶降解。

DNA连接酶: 双链DNA中一条链有切口，一端是3ˊ-OH，另一端是5ˊ-磷酸基，连接酶可催化这两端形成磷酸二酯键，而使切口连接，不能将两条游离的DNA单链连接起来。

在DNA复制、损伤修复、重组等过程中起重要作用。

拓扑异构酶(DNA Topisomerase):拓扑异构酶І：使DNA一条链发生断裂和再连接，作用是松解（消除）负超螺旋。

第二章染色体与DNA一、DNA的结构1、非组蛋白染色体蛋白负责30nm 纤丝高度有序的压缩( )2、因为组蛋白H4在所有物种中都是一样的，可以预期该蛋白质基因在不同物种中也是一样的。

（）3、DNA 在10nm 纤丝中压缩多少倍？（）4、A．6 倍B．10 倍C．40 倍D．240 倍E．1000 倍F．100005、染色体和DNA的区别是什么？答：是磷酸二酯键连接的简单核苷酸多聚体，其双链结构保证了依赖于模板合成的准确性，DNA 的以遗传密码的形式编码多肽和蛋白质，其编码形式多样而复杂。

6、染色体上的非组蛋白有什么功能？7、为什么只有DNA 适合作为遗传物质8、DNA三级结构有什么重要生物学意义9、下面叙述哪些是正确的？（C ）A．C 值与生物的形态复杂性呈正相关B．C 值与生物的形态复杂性呈负相关C．每个门的最小C 值与生物的形态复杂性是大致相关的10、下列哪些基因以典型的串联形式存在于真核生物基因组？( BC )A．珠蛋白基因B．组蛋白基因C．rRNA 基因D．肌动蛋白基因11、染色质非组蛋白的功能不包括（D）。

A．结构B．复制C．染色体分离D．核小体包装12、原核细胞DNA 的哪些特征表明了其基因组的组织方式具有经济性？13、为什么DNA 双螺旋中维持特定的沟很重要？14、高等真核生物的大部分DNA 是不编码蛋白质的。

（T ）15、酵母mRNA 的大小一般与基因的大小相一致，而哺乳动物mRNA 比对应的基因明显小是因为哺乳动物大部分基因含有内含子。

（T ）二、DNA的复制1．在DNA 合成中负责复制和修复的酶是DNA 聚合酶。

2．染色体中参与复制的活性区呈Y 开结构，称为DNA 复制叉。

3．在DNA 复制和修复过程中，修补DNA 螺旋上缺口的酶称为DNA 连接酶4．在DNA复制过程中，连续合成的子链称为前导链，另一条非连续合成的子链称为后随链。

5．如果DNA 聚合酶把一个不正确的核苷酸加到3′端，一个含3′→5′活性的独立催化区会将这个错配碱基切去。