生物化学与分子生物学考研测试题及答案

1、2011生物化学与分子生物学考研测试题及答案(1)研究生考试网 更新：2010-11-4 编辑：画心thea一、单项选择题1.维持蛋白质二级结构的主要化学键是：a.盐键 b.疏水键 c.肽键d.氢键 e.二硫键2.下列哪种碱基只存在于rna而不存在于dna：a.尿嘧啶b.腺嘌呤c.胞嘧啶d.鸟嘌呤e.胸腺嘧啶3.磺胺类药物的类似物是：a.四氢叶酸b.二氢叶酸c.对氨基苯甲酸d.叶酸e.嘧啶4.酶与一般催化剂的不同点，在于酶具有：a.酶可改变反应平衡常数b.极高催化效率c.对反应环境的高度不稳定d.高度专一性5.丙酮酸氧化脱羧生成乙酰辅酶a与许多维生素有关，但除外：a.b1b.b2c.b6d.p

2、pe.泛酸6.正常血浆脂蛋白按密度低高顺序的排列为：a.cmvldlidlldlb.cmvldlldlhdlc.vldlcmldlhdld.vldlldlidlhdle.vldlldlhdlcm7. 低密度脂蛋白：a.在血浆中由前-脂蛋白转变而来b.是在肝脏中合成的c.胆固醇含量最多d.富含apob1008. p/o比值是指：a.每消耗一分子氧所需消耗藁椎姆肿邮?brb.每消耗一分子氧所需消耗无机磷的克数c.每消耗一分子氧所需消耗无机磷的克原子数d.每消耗一分子氧所需消耗无机磷的克分子数e.每消耗一分子氧所需消耗无机磷的克数9.转氨酶的辅酶组分含有：a.泛酸b.吡哆醛(或吡哆胺)c.尼克酸d.

3、核黄素e.硫胺素10.最直接联系核苷酸合成与糖代谢的物质是：a.葡萄糖b.6磷酸葡萄糖c.1磷酸葡萄糖d.1，6二磷酸葡萄糖e.5磷酸葡萄糖二、多项选择题(在备选答案中有二个或二个以上是正确的，错选或未选全的均不给分)1.芳香族氨基酸是：a.苯丙氨酸 b.酪氨酸 c.色氨酸 d.脯氨酸2.dna水解后可得到下列哪些最终产物：a.磷酸b.核糖c.腺嘌呤、鸟嘌呤d.胞嘧啶、尿嘧啶3.1分子丙酮进入三羧酸循环及呼吸链氧化时：a.生成3分子co2b.生成15个atpc.有5次脱氢，均通过naoh进入呼吸链氧化生成h2od.所有反应均在线粒体内进行4.1分子丙酮进入三羧酸循环及呼吸链氧化时：a.生成3分

4、子co2b.生成15个atpc.有5次脱氢，均通过naoh进入呼吸链氧化生成h2od.所有反应均在线粒体内进行5.苹果酸天冬氨酸穿梭作用可以：a.生成3个atpb.将线粒体外nadh所带的氢转运入线粒体c.苹果酸和草酰乙酸可自由穿过线粒体内膜d.谷氨酸和天冬氨酸可自由穿过线粒体膜三、填空题1.蛋白质颗粒表面的_和_是蛋白质亲水胶体稳定的两个因素。2.乳酸脱氢酶(ldh)是_聚体，它由_和_亚基组成，有_种同工酶，其中ldh1含量最丰富的是_组织。3.丙酮酸脱氢酶系由丙酮酸脱氢酶、_和_组成。4.呼吸链的主要成份分为_、_、_、_和_。5.氨甲喋呤(mtx)干扰核苷酸合成是因为其结构与_相似，并

5、抑制_酶，进而影响一碳单位代谢。四、名词解释1.核酸的变性、复性(denaturation、renaturation)2.糖异生 (glycogenolysis)五、问答题1.计算下列各核酸水溶液在ph7.0，通过1.0cm光径杯时的260nm处的a值(消光度)。已知：amp的摩尔消光系数a260 = 15400gmp的摩尔消光系数a260 = 11700cmp的摩尔消光系数a260 = 7500ump的摩尔消光系数a260 = 9900dtmp的摩尔消光系数a260 = 9200求：(1)32mol/l amp，(2)47.5mol/l cmp，(3)6.0mol/l ump的消光度，(4)

6、48mol/l amp和32mol/l ump混合物的a260消光度。(5) a260 = 0.325的gmp溶液的摩尔浓度(以摩尔/升表示，溶液ph7.0)。(6) a260 = 0.090的dtmp溶液的摩尔浓度(以摩尔/升表示，溶液ph7.0)。如果人体有1014个细胞，每个体细胞的dna量为6.4109个碱基对。试计算人体dna的总长度是多少?是太阳-地球之间距离(2.2109公里)的多少倍?2.以乳糖操纵子为例说明酶诱导合成的调控过程?一、单项选择题1.d 2.a 3.c 4.b 5.c 6.b 7.e 8.b 9.a 3.10二、多项选择题1.abd 2.ac 3.bcd 4.ab

7、d 5.ac三、填空题1.电荷层 水化膜2.四 h m 5种 心肌3.硫辛酸乙酰移换酶 二氢硫辛酸脱氧酶4.尼克酰胺核苷酸类 黄素蛋白类 铁硫蛋白类 辅酶q 细胞色素类5.叶酸 二氢叶酸还原四、名词解释1. 核酸的变性、复性(denaturation、renaturation)：当呈双螺旋结构的dna溶液缓慢加热时，其中的氢键便断开，双链dna便脱解为单链，这叫做核酸的“溶解”或变性。在适宜的温度下，分散开的两条dna链可以完全重新结合成和原来一样的双股螺旋。这个dna螺旋的重组过程称为“复性”。2. 非糖物质(如丙酮酸 乳酸 甘油 生糖氨基酸等)转变为葡萄糖的过程。五、问答题1.答：已知：(

8、1) 32mol/l amp的 a260消光度a260 =3210-6 15400 = 0.493(2)47.5mol/l cmp的 a260消光度a260 =47.510-6 7500 = 0.356(3)6.0mol/l ump的a260消光度a260 =6.010-6 9900 = 0.0594(4)48mol/l amp和32mol/l ump混合物的a260消光度a260 =3210-6 9900 + 4810-6 15400 = 0.493 = 1.056(5)0.325/11700 = 2.78 10-5mol/l(6)0.090/9200 = 9.78 10-6mol/l2.

9、答：(1)乳糖操纵子：操纵子是指在转录水平上控制基因表达的协调单位，包括启动子(p)、操纵基因(o)和在功能上相关的几个结构基因，操纵子可受调节基因的控制。乳糖操纵子是三种乳糖分解酶的控制单位。(2)阻遏过程：在没有诱导物(乳糖)情况下，调节基因产生的活性阻遏蛋白与操纵基因结合，操纵基因被关闭，操纵子不转录。(3)诱导过程：当有诱导物(乳糖)的情况下，调节基因产生的活性阻遏蛋白与诱导物结合，使阻遏蛋白构象发生改变，失去与操纵基因结合的能力，操纵基因被开放，转录出三种乳糖分解酶(lacz、lacy、laca)。acknowledgements my deepest gratitude goes

10、first and foremost to professor aaa , my supervisor, for her constant encouragement and guidance. she has walked me through all the stages of the writing of this thesis. without her consistent and illuminating instruction, this thesis could not havereached its present form. second, i would like to e

11、xpress my heartfelt gratitude to professor aaa, who led me into the world of translation. i am also greatly indebted to the professors and teachers at the department of english: professor dddd, professor ssss, who have instructed and helped me a lot in the past two years. last my thanks would go to

12、my beloved family for their loving considerations and great confidence in me all through these years. i also owe my sincere gratitude to my friends and my fellow classmates who gave me their help and time in listening to me and helping me work out my problems during the difficult course of the thesi

13、s. my deepest gratitude goes first and foremost to professor aaa , my supervisor, for her constant encouragement and guidance. she has walked me through all the stages of the writing of this thesis. without her consistent and illuminating instruction, this thesis could not havereached its present fo

14、rm. second, i would like to express my heartfelt gratitude to professor aaa, who led me into the world of translation. i am also greatly indebted to the professors and teachers at the department of english: professor dddd, professor ssss, who have instructed and helped me a lot in the past two years. last my thanks would go to my beloved family for their loving considerations and great confidence in me