中山大学生科院 factor that determines the limit of resolution of a light microscope? 细胞生物学期中试卷 编码载脂蛋白B的基因在肠组织中转录成 (2001级生物科学、生物技术专业、进修 mRNA后,第2153位的C被 教师、交换生140人) 使CA密码转变成终止密码UAA,使翻 译提前终止 任课教师:王金发 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 2003年11月22日 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 姓名 专业 可与 填空题(每空05分,共5分) 二、判断以下各题是否正确,着正确,用T表示 决定红细胞ABO血型的物质是糖脂,它由 不正确用F表示并做简要说明。(每题1 脂肪酸和寡糖素链组成。A型血糖脂上的 分,共10分) 寡糖链较O型多 1. Both the gTP-bound a subunits and B型血 nucleotide-free Br complexes, but not GDP-bound, fully assembled G proteins 2.根据题意,将与A、B、C、D相对应的词 activate other molecules downstream 用连线连起来: linked receptors that are 答 analogous to human communication. 2. The density of water is less than the Decide which of the following forms of density of ice human communication analogous 3. Water has a high specific heat to autocrine, paracrine, endocrine, g and synaptic signaling by cells. 4. There is no fundamental distinction A. A telephone between signaling molecules that bind autocrine ose B. Talk to people at a cocktail that bind to intracellular receptors. endocrine 答 radio announcement: 5. How is it that different cells can ynaptic signaling espond in different Talking yourself signaling molecule even whe What is the major they have identical receptors?
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、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 following forms of human communication are analogous to 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 : paracrine 3. What is the major 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 subunits and nucleotide-free 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 signaling 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?
incorrect for the biogenesis of 6. Protein kinase a itself is different eukaryotic ribosomes?( in different cell types, which a. 25-50% of the pre-rrNa is explains why the effects of cyclic AMP degraded vary depending on the target b. Pre-rrna binds to ribosomal cell protein c. Pre-rrNA is cut to form three 7. It is thought that extracellular classes of rRNA ligand binding to a receptor d. Pre-rRNA is methylated e. The rrna gene for the 40S subunit kinase activates the intracellular is transcribed separately catalytic domain by propagating 2. The 5S rrNA differs from the other cellul a conformational change across the rRNAs in which of the following lipid bilayer through the singl transmembrane a heli a. The genes are located outside the 8. Atrial natriuretic peptides(心钠肽) b. The genes are transcribed by rna bind to a receptor that activates a G protein, which in turn activates c. The promoter region of the 5S rRNA guanylyl cyclase(鸟苷环化酶) to gene is internal to the gene clic GMP. which ther all of the aboy activates a cyclic GMP- dependent3.钙泵的作用主要是() protein kinase (PKG) a.降低细胞质中Ca2的浓度:b.提高 答 细胞质中Ca2的浓度 9. Because prokaryotic cells have c.降低内质网中Ca2的浓度;d.降低 neither mi tochondria nor chloroplasts. 线粒体中Ca+的浓度 they cannot carry out either ATP4. Plant guard cells(保卫细胞) have a synthesis or photosynthesis. higher [cl] than the outside 答 environment. The most likely 10.电镜的波长与电压有关,电压越高,波长 explanation for this is( 越短,分辨率越高 a. Water leaves the cell by osmosis transmembrane channels 三、选择题(请将正确答案的代号填入括号,毎 c. Cl-diffusion is aided by a mobile 题1分,共20分) carrier I. Which one of the following is d. An active transport symport
2 答: 6. Protein kinase A itself is different in different cell types, which explains 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 single transmembrane 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 mitochondria 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 ribosomal protein c. Pre-rRNA is cut to form three classes of rRNA d. Pre-rRNA is methylated e. The rRNA gene for the 40S subunit is transcribed separately 2. 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 are transcribed by RNA polymerase III. c. The promoter region of the 5S rRNA gene is internal to the gene. d. all of the above 3． 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 explanation 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 Cl-/H+ d. Two copies of each gene for rRNA and None of the above one copy of each ribosomal protein 5. The hormone glucagons(胰高血糖素) timulates the breakdown of stored 9. All of the following are true about glycogen in liver and muscle cells by antisense RNA except( he following enzymes. Which is the ement first enzyme that must be activated? b. Forms double-stranded rna C. Joins with the 30s subunit. a. Protein kinase a d. Inhibits protein synthesis. b. Phosphorylase kinase 10. Developing frog embryos treated with c. Glycogen phosphorylase anti-fibronectin antibodies d. Protein phosphatase a. Develop normally. e. Protein phosphatase inhibitor-l b. Stop cell division 6.在下列组织中,紧密连接特别重要的有 C. Have abnormal cell migration (if a. Stomach(H)and kidneys d. Don t exhibit action potentials. b. Smooth muscle 11.肌动蛋白纤维对于黏着斑就像()对 c. Heart muscle 于半桥粒。 d. Intestinal epithelial tissue(肠表 a.肌球蛋白纤维 b.角蛋白纤 皮组织) 7. Which one of the following was used to 微丝 d.钙粘着蛋 determine the structure of the DNA molecule? () 12.配体( ligand)是()。 a. Transmission(透射) electron a.酶与底物共价结合的活性位点 microscope b.酶与底物非共价结合的活性位点 b. Scanning electron microscope C.对于一个与蛋白质以共价形式相作 c. Differential centrifugation(差用的小分子的普遍称呼 速离心) d.对于一个与蛋白质以非共价形式相 d. X-ray crystallography 作用的小分子的普遍称呼 8. A eukaryotic cell has( e.一个缺乏酶活性的球蛋白 a. One copy of each ribosomal13.膜胆固醇的组成与质膜的性质、功能有着 transcription unit. 密切的关 b. Thousands of copies of the 5s rrNA a.胆固醇可防止膜磷脂氧化 gene. b.正常细胞恶变过程中,胆固醇/磷脂增 C. two f each gene for rRNA and n: ribosomal proteins c.胆固醇/磷脂下降,细胞电泳迁移率减
3 transports C1-/H+. e. None of the above 5. The hormone glucagons(胰 高 血糖 素 ) stimulates the breakdown of stored glycogen 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-1 6. 在下列组织中, 紧密连接特别重要的有 ( ) a. Stomach(胃) and kidneys b. Smooth muscle c. Heart muscle d. 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 crystallography 8. A eukaryotic cell 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 protein gene. 9. All of the following are true about antisense RNA except ( ) 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 action 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
microinjection(微注射) of Egta d.在质膜相变温度以下,增加胆固醇 glucagon-triggered 可以提高膜的流动性 14.用抗纤连蛋白的抗体注射胚体,发现在神 of glycogen(糖原) in liver? 经系统发育过程中神经嵴细胞的迁移受4. The basic structure of biological 到抑制。这些实验说明 embranes is determined by the a.神经嵴发育包括抗体基因的表达 lipid b.发育中的神经无需合成纤连蛋白: bilayer, but their specific functions C.纤连蛋白抗体复合物形成神经细胞 are carried out largely by proteins. 的迁移途径 d.胚胎中的神经元在移动过程中必须5. Why does a red blood cell membrane need 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 6. Describe the different methods that 后发生的事件是()。 cells use to restrict proteins to a.IRS的结合→具有SH2区域的蛋白 specific regions of the plasma 质的磷酸化→效应 membrane. Is a membrane with many b.与具有SH2区域的蛋白质结合→IRS anchored proteins still fluid 的磷酸化→效应 7. Transport by carrier proteins can be C.自磷酸化并将IRS磷酸化→与具有 either active or passive, whereas SH2区域的蛋白质结合→效应 transport by channel proteins is d.自磷酸化并与IRS结合→将具有SH2 always passive. Explain your 区域的蛋白质磷酸化→效应 answer 8. The signaling ms used by 四、简答题(毎题4分,共40分) steroid-hor 醇激素) 1. What functional roles do the ECM( receptor 胞外基质) and cell wall share in and by an ion-channel-linked receptor have very few components(组分).Can 2. Discuss the following analogy(相似) ther mechanism lead to an wThe differences between amplification of the initial signal? transporting a ligand by a channel or If so, how? a carrier protein are like the 9. Should RGs (regulator of G protein differences between crossing a river signaling) proteins be classified by a bridge or a ferry(摆渡). EFs (guanine nucleotide exchange 3. EGTA chelates(螯合) Ca with high factors) or GAPs (GTPase activating affinity and specificity. How proteins)? Explain what role this in modulating
4 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( )。 a．IRS 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 roles 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 and 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 red blood cell membrane need proteins? 6. Describe the different methods that cells use to restrict proteins to specific 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 proteins 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 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附加题(每题3分): animals and yeasts. 1. Proteins that span a membrane as an a 10. How is an IP3-triggered Ca" response helix have a characteristic te structure in the region of the bilayer. 五、简述第二信使cAMP的发现及生成的实 sequences listed below is the most 验证明(20分)。 likely candidate for such a transmembrane segment? Explain the 六、分析与思考(任选一题,20分) your choic tha A. ITLIYFGVMAGVIGTIL phosphory lation/dephosphorylation L I S plays such a prominent role in .ITPIYFGPMAGVIGTPL teins on and off in L I s signaling pathways? C.ITEIY FGRMAGVIGTDL he Ras protein functions as a molecular switch that is set t 2. Why are a helices more common than B Its on barrels in transmembrane proteins? state by a guanine-nucleotide exchange factor(GEF) that causes 3. Through the exchange of small metabolites and ions, gap junctions bind GTP. A GTPase-activating protein provide metabolic and electrical (GAP) resets the switch to the coupling between cells. Why, then, do off state by inducing Ras to hydrolyze you suppose that neurons communicate its bound gtp to gdp much primarily through synapses rapidly than in the absence of the GAP. Rather than through gap junctions? Thus Ras works like a light switch that one person turns on and anothe turns off. In a cell line that the Ras-specifi what ormalities would you expect to find in Ras activi nds to extracellular signals?
5 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(20 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 on state by a guanine-nucleotide exchange factor (GEF) that causes 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 expect to find in the way Ras activity responds to extracellular signals? 附加题(每题 3 分): 1. Proteins that span a membrane as an helix have a characteristic structure in the region of the bilayer. Which of the three 20-amino acid sequences listed below is the most likely candidate for such a transmembrane segment? Explain the reasons for your choice. A. I T L I Y F G V M A G V I G T I L L I S B. I T P I Y F G P M A G V I G T P L L I S C. I T E I Y F G R M A G V I G T D L L I S 2. Why are helices more common than barrels in transmembrane proteins? 3. Through the exchange of small metabolites and ions, gap junctions provide metabolic and electrical coupling between cells. Why, then, do you suppose that neurons communicate primarily through synapses ( 突 触)rather than through gap junctions?