细胞生物学期中试卷3
一、填空题(每空0.5分，共10分)
1. 细胞中水对于维持细胞温度的相对稳定具有重要作用，其原因是。
2. 纤粘连蛋白与细胞结合的结构域具有特征性的三肽结构，简称RGD序列，代表的三个氨基酸
是∶。
3. _ _ is an intracellular protein that binds calcium and activates enzymes.
4. A substance that fits into a specific binding site on the surface of a protein molecule is called a __ .
5. Two products of phospholipase C activity that serve as second messengers are _ and .
6.Cyclic AMP is produced by the enzyme _ _ and degraded by the enzyme _ _
7. NO是一种气体信号分子,在体内主要由精氨酸产生, 它的半衰期很短, 故只作用于邻近细胞, 它作用的靶酶是。
8. junctions enable cells to get a hold on the extracellular matrix by connecting their actin filaments to the
matrix.
9. 动物细胞质膜靠建立膜两侧的质子动力势，而植物细胞则是靠。
10. 蛋白质合成时多聚核糖体的形成对生命活动的意义在于: 。
11. 限制哺乳动物细胞体积大小的主要因素有两个:一种是的关系,另一种是。
12. Ca2+-ATPase是一个次跨膜的膜蛋白，有个细胞质环，工作时每次可以将个Ca2+
泵到细胞外。
13. 选择蛋白介导的细胞粘着是依赖性的, 而免疫球蛋白超家族蛋白介导的细胞粘着是依赖性的。
二、判断题(若是正确的标√号，错误的标×号，每题1分，共20分)
1. K+离子很难通过人工膜, 但加入短杆菌肽A后, 对K+的透性大大增加, 原因是短杆菌肽A可作为离子载体运输K+。( )
2. One can determine if a membrane protein is exposed on the external side of the plasma membrane by covalent attachment of
a labeling reagent or by protease digestion only if the membrane is intact. ( )
3. 脂锚定蛋白是通过蛋白的氨基酸残基同膜脂的脂肪酸链形成共价键而锚定在质膜上。( )
4. CsCl密度梯度离心法分离纯化样品时, 样品要和CsCl混匀后分装, 离心时, 样品中不同组分的重力不同, 停留在不同区带。( )
5. 载体蛋白, 又称为通透酶, 它象酶一样, 不能改变反应平衡,只能增加达到反应平衡的速度; 但与酶不同的是, 载体
蛋白不对被运的分子作任何修饰。( )
6. Ⅱ型内含子的剪接与核剪接机理相似, 都要形成剪接体和套索结构。( )
7. 5SrRNA是由RNA聚合酶Ⅱ转录的, 它使用的是内部启动子。( )
8. The surface area/volume ratio is generally greater for a prokaryotic cell than for a eukaryotic cell.（）
9. The ribosomes found in the mitochondria of your musde cells are more like those of the bacteria in your intestine than they are like the ribosomes in the cytosol of your musde cells.（）
10. Facilitated diffusion of a cation occurs only from a compartment of higher concentration to a compartment of lower
concentration.( )
11. Active transport is always driven by the hydrolysis of high-energy phosphate bonds.( )
12. Treatment of an animal cell with an inhibitor that is specific for the Na+/K+ pump is not likely to affect the uptake of glucose
by sodium cotransport.( )
13. Tight junctions get their name from their property of holding cells together so tightly that they cannot be separated by
mechanical forces.（）
14. Gap junctions connect the cytoskeletal elements of one cell to a neighboring cell or to the extracellular matrix.（）
15. NO acts only locally because it has a short half-life--about 5 to 10 seconds--in the extracellular space before it is converted
to nitrates and nitrites by oxygen and water.( )
16.Water-soluble signaling molecules, which have very short circulating life-times, usually mediate responses of short
duration, whereas water-insoluble ones, which persist in the blood for hours to days, tend to mediate longer-lasting responses.( )
