细胞生物学.docx

1、细胞生物学第五章Intracellular Compartments：细胞内的区域一.名词解释Compartmentalization：区分，划分；prokaryotic and eukaryotic cells：原核细胞和真核细胞Eucaryotic cells are subdivided into functionally distinct, membrane- enclosed compartments (organelles).真核细胞由膜分割成不同的区域（细胞器）secretory vesicles：分泌小泡endosome：内体，peroxisome：过氧化物酶体free pol

2、yribosomes:游离多聚核糖cytosol:细胞溶质lysomsome:溶酶体Golgi apparatus:高尔基体mitochondrion:线粒体endoplasmic reticulum with membrane-bound polyribosomes:内质网和与膜结合的多聚核糖体nucleus:细胞核plasma membrane:质膜Cytoplasmic matrix (Cytosol)：细胞质基质The Cytosol is the site of protein synthesis and degradation or modification. It also pe

3、rforms most of the cells intermediary metabolism.：细胞质是蛋白质合成和降解或修饰的位点。它还执行大多数细胞的中间代谢Endomembrane System：内膜系统Endoplasmic reticulum (ER), Golgi complex, endosomes, lysosome, and vesicles function as a coordinated unit.：内质网（ER） ，高尔基复合体，核内体，溶酶体，囊泡，充当一个协调单元。Other membranous organelles: mitochondria, chlor

4、oplasts, peroxisomes, and the nucleus.：其他膜质细胞器：线粒体，叶绿体，过氧化物酶体和细胞核中。exocytosis：胞吐 Endocytic：内吞secretory granule：分泌小泡Dynamic Nature of the Endomembrane System：内膜系统的动态性质Biosynthetic：生物合成二.五种检验分泌蛋白分泌途径的方法：1.Autoradiography：放射自显影：其原理是将放射性同位素（如14C和3H）标记的化合物导入生物体内，经过一段时间后，将标本制成切片或涂片，涂上卤化银乳胶，经一定时间的放射性曝光，组织中

5、的放射性即可使乳胶感光。然后经过显影、定影处理显示还原的黑色银颗粒，即可得知标本中标记物的准确位置和数量，放射自显影的切片还可再用染料染色，这样便可在显微镜下对标记上放射性的化合物进行定位或相对定量测定。 这种技术与电镜样品处理，则为电镜放射自显影。 2.Subcellular Fractionation：亚细胞分离Homogenization：同质化Differential Centrifugation：差速离心Microsome: a heterogeneous collection of vesicles formed from the endomembrane system (prim

6、arily ER and Golgi complex) after homogenization.：微粒：均化后，从内膜系统（主要是ER和高尔基体复合物）形成的囊泡的异构集合3.GFP:绿色荧光蛋白 YFP:黄色荧光蛋白 CFP：Cyan Fluorescent Protein青色荧光电白4. Cell-Free System：无细胞系统Fractionated cell homogenate that retains a particular biological function of the intact cell, and in which biochemical reactions

7、and cell processes can be more easily studied.：分级分离细胞匀浆保留了完整的细胞的特定的生物学功能，且其中生化反应和细胞过程可以更容易地分析。5. Genetic Mutants：基因突变RER is continuous with the outer membrane of the nuclear envelope.：粗面内质网与细胞核外膜相连。ribosome;核糖体interconnected相连的，（RER and SER are interconnected滑面内质网和粗面内质网）A. Functions of the SER滑面内质网的

8、功能1. Synthesis of steroids in endocrine cells. 在内分泌细胞类固醇的合成2.Detoxification of organic compounds in liver cells. 在肝细胞中合成解毒物质3. Release of glucose from glucose 6-phosphate in liver cells by the enzyme glucose 6-phosphatase. 在肝细胞内通过酶（葡萄糖-6 - 磷酸酶）从葡萄糖-6 - 磷酸释放葡萄糖。4.Sequestering Ca2+within the cytoplasm

9、 of skeletal and cardiac muscle cells. Ca2+-ATPase：螯合钙离子骨骼肌和心肌细胞的细胞质内。的Ca2 + -ATP酶B. Functions of the RER粗面内质网的功能1.Proteins synthesized on ribosomes of rER include:secretory proteins：分泌蛋白. integral membrane proteins. ：整合膜蛋白soluble proteins of organelles.：细胞器的可溶蛋白2.Modification and processing of newl

10、y synthesized proteins: glycosylation in the RER糖基化的粗面内质网The precursor oligosaccharide(14 sugars), which is transferred en blocto proteins in ER, is the same in plants, animals, and single- celled eukaryotes.N-linkage: N-连接N-linkage： linked to the amide nitrogen of asparagine (in ER).连接在天冬酰胺的N上面O-li

11、nkage: linked to the hydroxyl group of serine or threonine via GalNac (in Golgi complex)苏氨酸或丝氨酸Quality control of of newly synthesized proteins- The role of N-linked glycosylation in ER protein folding：新合成的蛋白质的质量控制- N-连接糖基化的内质网蛋白折叠中的作用Quality control: ensuring that misfolded proteins do not leave ER

12、：保证错误折叠的蛋白质不离开内质网The lumen of RER contains: Bip and calnexin (chaperones) that recognize and bind to unfolded or misfolded proteins and give them correct conformation. Protein disulfide isomerase ( PDI )粗面内质网内部有Bip和钙连接蛋白（伴侣），识别并整合到为折叠或者折叠错误的蛋白上，给他们正常的构象，蛋白质二硫键异构酶（PDI） GT(glucosyl-transferase, monito

13、ring enenzyme) recognize unfolded or misfolded proteins and adds a glucose to the end of oligosaccharide chains. GT （葡糖基转移酶，监测酶）识别未折叠或错误折叠的蛋白质，并添加了葡萄糖的寡糖链的末端。A Model of the Mammalian Unfolded Protein Response ：(UPR) 哺乳动物的未折叠蛋白反应（ UPR）的模型Inactive Sensors (BIP-bound ER transmembrane proteins)：传感器处于非活动

14、状态（ BIP结合ER跨膜蛋白）Activated Sensors (dimers) and BIP as chaperones：激活传感器（二聚体）和BIP作为分子伴侣Phosphorylation of one type of sensor and activation of other type of sensor by cleavage of the cytosolic domain, and diffusion into nucleus ：一种类型的传感器和激活的细胞内结构域的裂解其它类型的传感器，并扩散进入细胞核的磷酸化Signals that are transmitted in

15、to both the nucleus and cytosol被发送到这两个细胞核和细胞质中的信号Synthesis of membrane lipids膜脂质的合成Most membrane lipids are synthesized entirely within the ER. There are two exceptions: 大多数膜脂质在内质网合成有两个例外(1)Sphingomyelin and glycolipids (ER to Golgi complex). 鞘磷脂和糖脂（ER到高尔基复合体）(2) Some of the unique lipids of the mit

16、ochondrial and chloroplast membranes. 一些线粒体和叶绿体膜的独特脂质The membranes of different organelles have markedly different lipids composition. 不同的细胞器的膜具有明显不同的脂质成分。Membrane biosynthesis in the ER Membrane grow as newly synthesized proteins and lipids are inserted into existing membrane in the ER and move to

17、virtually every other compartments in the cell.在内质网中合成的脂质和蛋白质插在内质网的膜上随着内质网膜的移动运送的细胞各处Modifying the lipid composition of membranes修饰膜的脂质组成(1)Enzymatic modification of the head groups of phospholipids. 头部基团的磷脂的酶改性。(2) Different components in vesicles.不同成分的囊泡(3) Phospholipid-transfer proteins (phosphol

18、ipid translocators).磷脂转移蛋白1. Flippase 2,。Floppase3. Scramblase4. The Golgi Complex A. The polarity of Golgi complex高尔基复合体的极性cisFace: entry face closest to the ER. 靠近内质网cisGolgi network(CGN): interconnected network of tubules. 微管transFace: exit face farthest from the ER.远离内质网 transGolgi network (TGN)

19、: interconnected network of tubules and vesicles that sorts and targets proteins for delivery to their ultimate destination. 微管和囊泡进行排序和目标蛋白质运送到最终目的地的互连网络。cis, medial, and transcisternaeCisternae: flattened membrane-bound compartment.a) Reduced osmium tetroxide(OsO4) impregnates the ciscisternae. b)

20、Enzyme mannosidase II is localized in the medialcisternae. c) Enzyme nucleoside diphosphatase is localized in the transcisternae.Regional differences in membrane composition across the Golgi stackB. The Functions of Golgi complexGlycosylation in the Golgi complex.Assembly of carbohydrate component o

21、f glycoproteins and glycolipids. The core carbohydrate of N-linked oligosaccharides is assembled in the rER. Modifications to N-linked oligosaccharides are completed in the Golgi complex. O-linked oligosaccharides takes place in Golgi complex.The Golgi networks are processing and sorting stations wh

22、ere proteins are modified, segregated and then shipped in different directions.Transport within the Golgi apparatus -Cisternal maturation model and vesicular transport model5. Lysosomes A. Characteristics of LysosomesLysosome is a heterogenous organellePrimary lysosomes Secondary lysosomes Heteropha

23、gy Autophagy Residual bodyHistochemical visualization of lysosomes.Electron micrographs of two sections of a cell stained to reveal the location of acid phosphatase, a marker enzyme for lysosomes. The larger membrane-bounded organelles, containing dense precipitates of lead phosphate, are lysosomes,

24、 whose diverse morphology reflects variations in the amount and nature of the material they are digesting. Lysosomes contain acid hydrolases that can digest virtually every type of biological macromolecule. Marker enzyme: acid phosphataseLysosome membrane: H+-pumps: internal proton concentration is

25、kept high by H+- ATPase. Glycosylated proteins protect the lysosome from self-digestion. Transport proteins: transporting digested materials.Proteins labeled with a pH- sensitive fluorescent probe (fluorescein) and then endocytosed by cells can be used to measure the pH in endosomes and lysosomes. T

26、he different colors reflect the pH that the fluorescent probe encounters in these organelles. The pH in lysosomes (red) is about 5, while the pH in various types of endosomes (blue and green) ranges from 5.5 to 6.5. (Courtesy of Fred Maxfield and Kenneth Dunn.) The Low pH in Lysosomes and EndosomesB

27、. The Functions of Lysosomes Lysosomes are involved in three major cell functions phagocytosis; autophagy; endocytosisPrimary lysosomes fuse with either phagocytic or autophagic vesicles, forming residual bodies that either undergo exocytosis or are retained in the cell as lipofuscin granules.The Au

28、tophagic Pathway6. The Cell NucleusA. A Typical Nonmitotic Nucleus Includes Several Major ComponentsB. The Nuclear Envelope Consists of Two MembranesC. The Nuclear LaminaThe inner surface of the nuclear envelope is lined by the nuclear lamina, which provides the mechanical support to the nuclear env

29、elop and serves as a site of attachment for chromatin fibers at the nuclear periphery.The nuclear lamina is composed of lamins.The integrity of the nuclear lamina is regulated by phosphorylation and dephosphorylationD. The Nuclear Pore Complex (NPC)The Arrangement of NPCs in the Nuclear EnvelopeA Mo

30、del of A Vertebrate NPCThe Cytoplasmic Face of NPCThe Nuclear Face of NPCMolecules enter and exit the nucleus through nuclear pore complex第一章：细胞生物学 Cell Biology What are the fundamental properties that characterize living things and distinguish them from nonliving matter?All living things are made o

31、fCellsChapter 1The Development of Cell The Realization of the Importance of Cells as the Structural Unit of Life 1. The Discovery of CellsThe Invention of MicroscopeThe microscope used by Robert Hooke and the honeycomb-like network of “cell”he drawed in 1665.In 1665, Robert Hooke saw a network of ti

32、ny boxlike compartments that reminded him of a honeycomb. He called these little compartments “cellulae”, a Latin term meaning little room. It is from this word we get our present-day term, cell. The Discovery of Cells2. Cell Theory1. All organisms are composed of one or more cells.2. The cell is the basic unit of structure and function for all organisms.3. All cells arise only from preexisting cells by division. 2. 细胞理论