中山大学生科院

1、 中山大学生科院 细胞生物学期中试卷 (2001级生物科学、生物技术专业、进修教师、交换生,140人) 任课教师 王金发 2003年11月22日 姓 名 专 业 一 二 三 四 五 六 总 分一、填空题(每空0.5分，共5分)1. 决定红细胞ABO血型的物质是糖脂，它由脂肪酸和寡糖素链组成。A型血糖脂上的寡糖链较O型多一个 ；B型血仅多一个 。2. 根据题意, 将与A、B、C、D相对应的词用连线连起来:Cells communicate in ways that are analogous to human communication. Decide which of the followin

2、g forms of human communication are analogousto autocrine, paracrine, endocrine, and synaptic signaling by cells. A. A telephone conversation: autocrine B. Talking to people at a cocktail party: endocrine C. A radio announcement: synaptic signaling D. Talking to yourself : paracrine3. What is the maj

3、or factor that determines the limit of resolution of a light microscope?4. 编码载脂蛋白B的基因在肠组织中转录成mRNA后,第2153位的C被 形成U,使CAA密码转变成终止密码UAA, 使翻译提前终止。5. 是细胞外基质的受体蛋白。在结构上，它们是异二聚体，。这种跨膜蛋白的细胞外部分有一个球形的头部，可与细胞外基质蛋白结合，而细胞质结构域则可与 相结合。二、判断以下各题是否正确, 若正确, 用T表示, 不正确用F表示,并做简要说明。 (每题1分，共10分)1. Both the GTP-bound a subunits

4、 and nucleotide-free b¡ complexes, but not GDP-bound, fully assembled G proteins, activate other molecules downstream of G-protein-linked receptors. 答:2. The density of water is less than the density of ice.答:3. Water has a high specific heat.答:4. There is no fundamental distinction between sig

5、naling molecules that bind to cell-surface receptors and those that bind to intracellular receptors. 答:5. How is it that different cells can respond in different ways to exactly the same signaling molecule even when they have identical receptors?答:6. Protein kinase A itself is different in different

6、 cell types, whichexplains why the effects of cyclic AMP vary depending on the target cell.答:7. It is thought that extracellular ligand binding to a receptor tyrosine kinase activates the intracellular catalytic domain by propagating a conformational change across the lipid bilayer through the singl

7、e transmembrane a helix. 答:8. Atrial natriuretic peptides(心钠肽) bind to a receptor that activates a G protein,which in turn activates guanylyl cyclase(鸟苷环化酶) to produce cyclic GMP which then activates a cyclic GMP-dependent protein kinase (PKG). 答:9. Because prokaryotic cells have neither mitochondri

8、a nor chloroplasts, they cannot carry out either ATP synthesis or photosynthesis.答:10电镜的波长与电压有关，电压越高，波长越短，分辨率越高。答:三、选择题(请将正确答案的代号填入括号，每题1分，共20分)1. Which one of the following is incorrect for the biogenesis of eukaryotic ribosomes?( ) a. 25-50% of the pre-rRNA is degraded b. Pre-rRNA binds to ribosom

9、al protein c. Pre-rRNA is cut to form three classes of rRNA d. Pre-rRNA is methylatede. The rRNA gene for the 40S subunit is transcribed separately2. The 5S rRNA differs from the other cellular rRNAs in which of the following ways? ( ) a. The genes are located outside the nucleolus(核仁). b. The genes

10、 are transcribed by RNA polymerase III. c. The promoter region of the 5S rRNA gene is internal to the gene.d. all of the above3 钙泵的作用主要是( )。 a降低细胞质中Ca2+的浓度； b提高细胞质中Ca2+的浓度； c降低内质网中Ca2+的浓度； d降低线粒体中Ca2+的浓度 4. Plant guard cells(保卫细胞) have a higher C1- than the outside environment. The most likely expla

11、nation for this is( ). a. Water leaves the cell by osmosis. b. C1- is diffusing through transmembrane channels. c. C1- diffusion is aided by a mobile carrier. d. An active transport symport transports C1-/H+.e. None of the above5. The hormone glucagons(胰高血糖素) stimulates the breakdown of stored glyco

12、gen in liver and muscle cells by the following enzymes. Which is the first enzyme that must be activated? ( ) a. Protein kinase A b. Phosphorylase kinase c. Glycogen phosphorylase d. Protein phosphatase e. Protein phosphatase inhibitor-16. 在下列组织中, 紧密连接特别重要的有( )a. Stomach(胃) and kidneysb. Smooth musc

13、lec. Heart muscled. Intestinal epithelial tissue(肠表皮组织)7. Which one of the following was used to determine the structure of the DNA molecule? ( ) a. Transmission(透射) electron microscope b. Scanning electron microscope c. Differential centrifugatioin(差速离心)d. X-ray crystallography8. A eukaryotic cell

14、has( ) a. One copy of each ribosomal transcription unit. b. Thousands of copies of the 5S rRNA gene. c. Two copies of each gene for rRNA and ribosomal proteins. d. Two copies of each gene for rRNA and one copy of each ribosomal proteingene.9. All of the following are true about antisense RNA except

15、( ) a. Is complementary to mRNA. b. Forms double-stranded RNA. c. Joins with the 30S subunit. d. Inhibits protein synthesis.10. Developing frog embryos treated with anti-fibronectin antibodies a. Develop normally.( ) b. Stop cell division. c. Have abnormal cell migration(迁移). d. Don't exhibit ac

16、tion potentials.11肌动蛋白纤维对于黏着斑就像( )对于半桥粒。a肌球蛋白纤维 b角蛋白纤维c微丝 d钙粘着蛋白12配体(ligand)是（ ）。a酶与底物共价结合的活性位点；b酶与底物非共价结合的活性位点；c对于一个与蛋白质以共价形式相作用的小分子的普遍称呼；d对于一个与蛋白质以非共价形式相作用的小分子的普遍称呼；e一个缺乏酶活性的球蛋白13膜胆固醇的组成与质膜的性质、功能有着密切的关系,（ ） a胆固醇可防止膜磷脂氧化； b正常细胞恶变过程中，胆固醇/磷脂增加； c胆固醇/磷脂下降，细胞电泳迁移率减少； d在质膜相变温度以下，增加胆固醇，可以提高膜的流动性14用抗纤连蛋白的

17、抗体注射胚体，发现在神经系统发育过程中神经嵴细胞的迁移受到抑制。这些实验说明：( )a神经嵴发育包括抗体基因的表达；b发育中的神经无需合成纤连蛋白；c纤连蛋白/抗体复合物形成神经细胞的迁移途径；d胚胎中的神经元在移动过程中必须与纤连蛋白暂时结合15当胰岛素与其受体酪氨酸激酶结合后，随后发生的事件是( )。aIRS的结合具有SH2区域的蛋白质的磷酸化效应；b与具有SH2区域的蛋白质结合IRS的磷酸化效应；c自磷酸化并将IRS磷酸化与具有SH2区域的蛋白质结合效应；d自磷酸化并与IRS结合将具有SH2区域的蛋白质磷酸化效应四、简答题(每题4分，共40分)1. What functional rol

18、es do the ECM (细胞外基质)and cell wall share in common?2. Discuss the following analogy(相似): “The differences between transporting a ligand by a channel or a carrier protein are like the differences between crossing a river by a bridge or a ferry(摆渡)."3. EGTA chelates(螯合) Ca2+ with high affinity an

19、d specificity. How would microinjection(微注射) of EGTA affect glucagon-triggered breakdown of glycogen (糖原) in liver?4. The basic structure of biological membranes is determined by the lipid bilayer, but their specific functions are carried out largely by proteins. Explain your answer.5. Why does a re

20、d blood cell membrane need proteins?6. Describe the different methods that cells use to restrict proteins tospecific regions of the plasma membrane. Is a membrane with many anchored proteins still fluid?7. Transport by carrier proteins can be either active or passive, whereas transport by channel pr

21、oteins is always passive. Explain your answer.8. The signaling mechanisms used by a steroid-hormone(固醇激素) receptor and by an ion-channel-linked receptor have very few components(组分). Can either mechanism lead to an amplification of the initial signal? If so, how?9. Should RGS (regulator of G protein

22、 signaling) proteins be classified as GEFs (guanine nucleotide exchange factors) or GAPs (GTPase activating proteins)? Explain what role this activity plays in modulating G-protein-mediated responses in animals and yeasts.10. How is an IP3-triggered Ca2+ response terminated?五、简述第二信使cAMP的发现及生成的实验证明(2

23、0分)。六、分析与思考(任选一题, 20分)1. Why do you suppose that phosphorylation/dephosphorylation, plays such a prominent role in switching proteins on and off in signaling pathways?2. The Ras protein functions as a molecular switch that is set to its onstate by a guanine-nucleotide exchange factor (GEF) that caus

24、es it to bind GTP. A GTPase-activating protein (GAP) resets the switch to the off state by inducing Ras to hydrolyze its bound GTP to GDP much more rapidly than in the absence of the GAP. Thus Ras works like a light switch that one person turns on and another turns off. In a cell line that lacks the Ras-specific GAP, what abnormalities would you e