<P >清华大学<FONT face="Times New Roman">98</FONT>硕士入学生化试题</P>
<P >一．<FONT face="Times New Roman"> </FONT>名词解释（<FONT face="Times New Roman">20</FONT>分）</P>
<P >⑴构象和构型<FONT face="Times New Roman">(Conformation and Configuration) </FONT>⑵辅酶和辅基<FONT face="Times New Roman">(Prosthetic group and Coenzyme) </FONT></P>
<P >⑶别构酶和共价调节酶<FONT face="Times New Roman">(Allosteric enzymes and Covalent regulatory enzymes) </FONT></P>
<P >⑷氧化磷酸化和底物水平磷酸化<FONT face="Times New Roman">(oxidative phosphorylation and substrate level</FONT></P>
<P ><FONT face="Times New Roman">phosphorylation)</FONT>⑸半保留复制和逆转录<FONT face="Times New Roman">(Semiconservative replication and Reverse transcription) </FONT></P>
<P >⑹呼吸链<FONT face="Times New Roman">(Respiratory) </FONT>⑺必需脂肪酸<FONT face="Times New Roman">(Essential fatty acids) </FONT>⑻光合作用的光反应和暗反应<FONT face="Times New Roman">(Light</FONT></P>
<P ><FONT face="Times New Roman">reation and Dark reation of the photosynthesis) </FONT>⑼变偶学说<FONT face="Times New Roman">(Wobble hypothesis) </FONT></P>
<P >⑽克隆和突变<FONT face="Times New Roman">(Cloning and Mutation)</FONT></P>
<P >二．<FONT face="Times New Roman"> </FONT>写出下列化合物结构式（<FONT face="Times New Roman">20</FONT>分）</P>
<P >⑴葡萄糖醛酸<FONT face="Times New Roman">(Glucouronic acid) </FONT>⑵<FONT face="Times New Roman">4-</FONT>羟基脯氨酸<FONT face="Times New Roman">(4-Hydroxyproline) </FONT></P>
<P >⑶异硫氰酸苯脂<FONT face="Times New Roman">(Phenylisothiocyanate) </FONT>⑷生物素<FONT face="Times New Roman">(biotin) </FONT>⑸鸟氨酸<FONT face="Times New Roman">(ornithine) </FONT></P>
<P >⑹苯丙氨酰丝氨酸<FONT face="Times New Roman">(Phenylalanylserine) </FONT>⑺磷酸烯醇式丙酮酸<FONT face="Times New Roman">(phosphoenolpyruvate) </FONT></P>
<P >⑻<FONT face="Times New Roman">L-</FONT>苹果酸<FONT face="Times New Roman">(L-malate) </FONT>⑼延胡索酸<FONT face="Times New Roman">(Fumarate) </FONT>⑽胍氨酸<FONT face="Times New Roman">(Citruline)</FONT></P>
<P >三．<FONT face="Times New Roman"> </FONT>完成下列酶催化反应方程式（<FONT face="Times New Roman">20</FONT>分）</P>
<P >⑴谷丙转氨酶<FONT face="Times New Roman">(glutamate alanine aminotransferase) </FONT></P>
<P >⑵<FONT face="Times New Roman">D-</FONT>甘油醛<FONT face="Times New Roman">-3-</FONT>磷酸脱氢酶<FONT face="Times New Roman">(D-glyceraldehyde-3-phosphate dehydrogenase) </FONT>⑶丙酮酸激酶<FONT face="Times New Roman">(pyruvate kinase)</FONT></P>
<P >⑷延胡索酸酶<FONT face="Times New Roman">(fumarase) </FONT>⑸柠檬酸合成酶<FONT face="Times New Roman">(citrate synthase) </FONT>⑹琥珀酸脱氢酶<FONT face="Times New Roman">(succinate dehydrogenase) </FONT></P>
<P >⑺精氨琥珀酸合成酶<FONT face="Times New Roman">(arginino succinate synthetase) </FONT>⑻精氨酸酶<FONT face="Times New Roman">(arginase) </FONT></P>
<P >⑼果糖<FONT face="Times New Roman">-1</FONT>，<FONT face="Times New Roman">6-</FONT>二磷酸酶<FONT face="Times New Roman">(fructose-1,6-diphosphatase) </FONT>⑽甲硫氨酰<FONT face="Times New Roman">-tRNA</FONT>合成酶<FONT face="Times New Roman">(Met-tRNA synthetase)</FONT></P>
<P >四．<FONT face="Times New Roman"> </FONT>判断下列是非题（若是在括号内标上“<FONT face="Times New Roman">+</FONT>”，若非标上“—”）（<FONT face="Times New Roman">10</FONT>分）</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑴用热水溶解淀粉时，可溶的部分为支链淀粉，不溶解的部分为直链淀粉。</P>
<P >（</P>
<P >）⑵<FONT face="Times New Roman">Lys</FONT>在人体内可以通过复杂的合成途径合成，是人体生物合成所必需的氨基酸，故为“必需氨基酸”之一。</P>
<P >（</P>
<P >）⑶寡聚蛋白质中亚基与亚基的相互作用的主要作用力是氢键和离子键，因为增加离子强度可以使寡聚蛋白解聚为单体。</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑷在完整细胞内的某一代谢过程中由几个酶催化的反应链体系，称为多酶体系。</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑸通常把<FONT face="Times New Roman">DNA</FONT>变性时，即双螺旋结构完全丧失时的温度称为<FONT face="Times New Roman">DNA</FONT>的熔点，用<FONT face="Times New Roman">Tm</FONT>表示。</P>
<P >（</P>
<P >）⑹嘌呤霉素具有氨酰<FONT face="Times New Roman">tRNA3</FONT>′端的类似结构，它阻止了甲硫氨酰<FONT face="Times New Roman">tRNA</FONT>与核糖体的结合，从而抑制了蛋白质合成的起始。</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑺<FONT face="Times New Roman">2</FONT>，<FONT face="Times New Roman">4-</FONT>二硝基甲苯是一种解偶联剂，是破坏呼吸链电子传递和<FONT face="Times New Roman">ATP</FONT>合成之间的偶联关系。</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑻经<FONT face="Times New Roman">Urea cycle</FONT>合成的<FONT face="Times New Roman">Urea</FONT>分子中两个–<FONT face="Times New Roman">NH2</FONT>，均是来自线粒体内游离氨经氨甲酰基磷酸而掺入。</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑼<FONT face="Times New Roman">HIV</FONT>是一种<FONT face="Times New Roman">RNA</FONT>病毒，在每一个病毒中有两条<FONT face="Times New Roman">RNA</FONT>链。</P>
<P >（<FONT face="Times New Roman"> </FONT>）⑽<FONT face="Times New Roman">Motif</FONT>指的是蛋白质分子结构中介于二级结构与三级结构之间的一个结构层次，又称超二级结构。</P>
<P >五．<FONT face="Times New Roman"> </FONT>问答题（<FONT face="Times New Roman">30</FONT>分）</P>
<P >⑴请叙述<FONT face="Times New Roman">DNA</FONT>双螺旋结构的要点。</P>
<P >⑵有一个七肽，经分析它的氨基酸组成是：<FONT face="Times New Roman">Lys,Pro,Arg,Phe,Ala,Tyr,</FONT>和<FONT face="Times New Roman">Ser</FONT>。此肽未经糜蛋白酶处理时，与<FONT face="Times New Roman">FDNB</FONT>反应不产生α<FONT face="Times New Roman">-DNP-</FONT>氨基酸。经糜蛋白酶作用后，此肽断裂成两个肽段，其氨基酸组成分别为<FONT face="Times New Roman">Ala,Tyr,Ser</FONT>和<FONT face="Times New Roman">Pro,Phe,Lys,Arg</FONT>。这两个肽段分别与<FONT face="Times New Roman">FDNB</FONT>反应，可分别产生<FONT face="Times New Roman">DNP-Ser</FONT>和<FONT face="Times New Roman">DNP-Lys</FONT>。此肽与胰蛋白酶反应，同样能生成两个肽段，它们的氨基酸组成分别是<FONT face="Times New Roman">Arg,Pro</FONT>和<FONT face="Times New Roman">Phe,Tyr,Lys,Ser,Ala</FONT>。试问此七肽的一级结构是怎样的？给出分析过程。</P>
<P >⑶什麽是生物膜的“流体镶嵌”模型？请叙述其结构特点。</P>
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