中山大学《细胞生物学》思考题 08.doc

豆萁中山大学考研论坛 ting & Thinking of Cell Biology 08. 11. 16 you think of the protein asa traveler, what kind of vehicle would best describe the sorting receptor: a private car, a taxi, ora bus? Explain your choice. 答案: taxi 。知识点:蛋白质分选受体 2. The ER lumen contains a mixture of thiol-containing reducing agents that prevent the formation of S-S linkages(disulfide bonds) by maintaining the cysteine( 半胱氨酸) side chains of lumen proteins in reduced(-SH) form. 答案: 判断题。知识点: 二硫键在哪里形成, 形成它的机制和阻止它形成的物质各是什么。该物质不存在于内质网的腔中,故题目错误。 3. Where would you expect to see microsomes ( 微粒体) in an electron micrograph ofa liver cell? 答案:误导。因为活的细胞中没有微粒体,不存在于生活细胞中。是人工造成的,在分离细胞内膜结构时,大的膜结构破裂而造成的。 4. Why might it be advantageous to add a preassembled block of 14 sugars toa protein in the ER, rather than building the sugar chains step-by-step on the surface of the protein by the sequential addition of sugars by individual enzymes? 答案:科学发展观…优势:质量高、快速、经济(即节约) (?高尔基体中,糖基是一步一步添加的…) 11. 24 Patients with Hunter ’s syndrome or with Hurler ’s syndrome rarely live beyond their teens. These parients accumulate glycoasaminoglycans in lysosomes due to the lack of specific lysosomal enzymes necessary for their degradation . When cells from patients with the two syndromes are fused, glycosominoglycans are degraded properly, indicating that the cells are missing different degradative enzymes. Even if the cells are just cultured