Question.What do telomeres do?a.They protectthe chromsomesfrom degradationbynucleases.b. They preventthe ends of chromosomesfrom fusing with one another.c.They arerequiredfor completechromosomalreplicationd.all of theabove2, Foreach of thefollowing sentences,fill inthe blanks with the best word or phraseselected from the list below. Not all words or phrases will be used; each word or phraseshould be used only once.Eucaryotic cells are bigger and more elaborate than procaryotic cells. By definition, alleucaryotic cells have a , usually the most prominent organelle in the eucaryotic cell.Another organelle found in essentially all eucaryotic cells is the, which generates thechemical energy for the cell. On the other hand, a(n),can be found only in the cells ofplants and algae, and performs photosynthesis. If we were to strip away the plasmamembrane from a eucaryotic cell and remove all ofits membrane-enclosed organelles, wewould be left with the , which contains many long, fine filaments of protein that areresponsible for cellshape and structure and thereby form the cell's福(a)chloroplast(d)cytosol (ac)nucleus(b)chromosome (e)endoplasmicreticulum (ad)ribosomes(c)cytoskeleton (ab)mitochondrion
1. What do telomeres do? a. They protect the chromsomes from degradation by nucleases. b. They prevent the ends of chromosomes from fusing with one another. c. They are required for complete chromosomal replication. d. all of the above Question 2、For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once. Eucaryotic cells are bigger and more elaborate than procaryotic cells. By definition, all eucaryotic cells have a_, usually the most prominent organelle in the eucaryotic cell. Another organelle found in essentially all eucaryotic cells is the _, which generates the chemical energy for the cell. On the other hand, a(n) _,can be found only in the cells of plants and algae, and performs photosynthesis. If we were to strip away the plasma membrane from a eucaryotic cell and remove all of its membrane-enclosed organelles, we would be left with the _, which contains many long, fine filaments of protein that are responsible for cell shape and structure and thereby form the cell’s _, (a) chloroplast (d) cytosol (ac) nucleus (b) chromosome (e) endoplasmic reticulum (ad) ribosomes (c) cytoskeleton (ab) mitochondrion
Testing and ThinkingImmotile cilia syndrome patients havedefectiveA.myosin B.tubulin C.dynein D.actinWhat mechanism is responsible formovements of cilia and flagella?A Kinesin moving on microfilamentsB.Dynein moving on microfilamentsCDynein movinonmicrotubuesD.Myosin moving on microfilaments
Immotile cilia syndrome patients have defective _. A. myosin B. tubulin C. dynein D. actin Testing and Thinking What mechanism is responsible for movements of cilia and flagella? A. Kinesin moving on microfilaments B. Dynein moving on microfilaments C. Dynein moving on microtubules D. Myosin moving on microfilaments
C.dyneinDynein is the molecular motor responsiblefor the movement of microtubules in ciliaand flagella. The defect in immotile ciliasyndrome is caused by alterations in dyneinC.Dynein moving on microtubulesDynein is the correct motor for microtubulesfunctional as cilia and flagella
C. dynein Dynein is the molecular motor responsible for the movement of microtubules in cilia and flagella. The defect in immotile cilia syndrome is caused by alterations in dynein. C. Dynein moving on microtubules Dynein is the correct motor for microtubules functional as cilia and flagella
一、判断1.在微管的组装中.需要GTP水解供给能量2.在微丝的装配中必须通过ATP水解才能装配。3.植物细胞的MTOC是中心粒微管是高度动态的结构，既能生长,也能缩短。通4.1过将亚基添加到正端来生长，而从负端除去亚基使微管缩短。答：F，GTP的主要作用不是供给能量，而是同o微管蛋白二聚体结合后，才能作为组装的基本构件结合到组装的微管上2答：F，虽然结合的ATP常被水解成ADP但是对于F-肌动蛋白的装配来说ATP的水解不是必要的过程因为含有ADP或不能水解的ATP类似物的G肌动蛋白装配后都是稳定的。答：E，植物细胞没有中心粒3.答：F，两端都能生长，只不过正端快些4
1. 在微管的组装中,需要GTP水解供给能量。 2. 在微丝的装配中,必须通过ATP水解才能装配。 3. 植物细胞的MTOC是中心粒。 4. 微管是高度动态的结构, 既能生长,也能缩短。通 过将亚基添加到正端来生长,而从负端除去亚基使 微管缩短。 一、判断 1. 答: F, GTP的主要作用不是供给能量, 而是同αβ微管蛋白二聚体结合后,才 能作为组装的基本构件结合到组装的微管上。 2. 答: F ,虽然结合的ATP常被水解成ADP,但是对于F-肌动蛋白的装配来说， ATP的水解不是必要的过程，因为含有ADP或不能水解的ATP类似物的G- 肌动蛋白装配后都是稳定的。 3. 答: F, 植物细胞没有中心粒; 4. 答: F, 两端都能生长,只不过正端快些;
微管蛋白异二聚体的α和β两个亚基都能同GTP结合，亲5.和力也一样。6.中心粒是微管组织中心的主要成分，并且都是成对存在的。7.决定微管稳定性的两个因素是游离微管蛋白的浓度和GTP水解的速率。中间纤维通过桥粒将相邻的细胞连成一体。8.5.答：F,不一样,α亚基结合GTP后不被水解,也不与GDP交换，而β亚基上的GTP结合位点是可交换位点答：F；在基体中只有一个中心粒：6.答:T;7.8.答:T;
5. 微管蛋白异二聚体的α和β两个亚基都能同GTP结合, 亲 和力也一样。 6.中心粒是微管组织中心的主要成分，并且都是成对存在的。 7. 决定微管稳定性的两个因素是游离微管蛋白的浓度和GTP 水解的速率。 8. 中间纤维通过桥粒将相邻的细胞连成一体。 5. 答: F, 不一样,α亚基结合GTP后不被水解, 也不与GDP交换, 而β亚基上的 GTP结合位点是可交换位点; 6. 答: F; 在基体中只有一个中心粒; 7. 答: T; 8. 答:T；