细胞生物学1.Introductionofcellbiology.ppt

Welcome Each of You to My Class Feb. - July 2013 Cell Biology The structure of cells structure function molecular mechanisms of the intri- cate activities of cells 细胞生物学是： 研究细胞基本 生命活动规律 的科学，它从 不同层次上主 要研究 The course mainly covers: Chapter 1: Introduction to Cell Biology (第一、二章) Chapter 2: Techniques in Cell Biology (第三章) Chapter 3: Cytoplasmic Membrane and The Movement of Substances Across Cell Membranes (第四、五章) chapter 4: Energy Generation in Mitochondria and Chloroplasts (第六章) Chapter 5: Cytoplasmic matrix, Endomembrane system, Protein Sorting and membrane trafficking (第七章) Chapter 6: Cell Signaling （第八章） Chapter 7: Cytoskeleton System （第九章） Chapter 8: Nucleus and Chromosomes （第十章） Chapter 9: Ribosome (第十一章) Chapter 10: Cell proliferation and its regulation （第十二章） Chapter 11: Cell apoptosis and cellular aging (第十三章) Chapter 12: Cell differentiation and gene expression (第十四章) Chapter 13: Cell Community Relation: Cell Junctions, Cell Adhesion and Extracellular Matrix (第十五章) Reference books and journals 翟中和，王喜忠，丁明孝 主编， 细胞生物学，高等教育出版社，第 三版，2007 Gerald Karp. Cell and Molecular Biology：concepts and experiments，4rd Edition. Published by John Wiley 3rd 2002. Becker W.M. et al. The World of the Cell. 4th Ed. The Benjamin/Cummings Publishing Company. 2000. b Fundamental Concepts and theories b Experimental approaches and ideas (As you read this text, think like a researcher) b Reductionist (knowledge of the parts of the whole can explain the character of the whole) b Dont accept everything you read as being true. Remain skeptical! b English is just a tool! bTake notes when you listened especially what I have emphasized Suggestions to Study Cell Biology Chapter 1 Introduction to the cells 1. About Cell Biology 2. Look briefly at the history of cell theory 3. Why are cells the basic units of life? 4. Consider the basic properties of cells 5. Types of Prokaryotic Cells: Two Subkingdoms 6. Types of eukaryotic cells and structural system 7. The size of cells 8. Relationship between structure and function of cells 9. Characteristics that distinguish prokaryotic and eukaryotic cells 10. Comprehend a special life: viruses Learning Objectives 1. About “Cell Biology”（研究内容与现状） Nucleus, Chromosomes and gene expression Cytoplasmic Membrane (Bio-membrane) Cell organelle (Mitochondria, Chloroplasts, Endomembrane system, nucleus etc.) Cytoskeleton System Cell proliferation and regulation Cell differentiation and gene expression Cell apoptosis and cellular aging Cell origins and evolutions Cell engineering Cell signaling See p.3-5 2. The Cell Theory: A Brief History 发现细发现细 胞（Robert Hooke，1665） 建立细细胞学说说 （施莱登，施旺，1838-1839 ） 细细胞 学的经经典时时期 （19世纪纪最后25年，广泛的观观察与描述） 实验细实验细 胞生物学时时期 （应应用实验实验 的手段与分析方法进进行研究 ） 细细胞生物学学科的形成与发发展 P8-13 The discovery of Cells In 1665, Robert Hooke saw a network of tiny 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. P8 The microscope used by Robert Hooke and the honeycomb-like network of “cell” he drew in 1665 The discovery of cells followed from the invention of the microscope Three basic tenets of Cell theory 1. All organisms are composed of one or more cells. 2.The cell is basic unit of structure and function for all organisms. 3.All cells arise only from preexisting cells by division. P9 3. Why are cells the basic units of life? A. The cell is the structural unit of life, All organisms is make up of cells. P19-21 B. The cell is the functional unit of organisms. All metabolic activity is based on cells. 独立的 有序的 自控的 C. The cell is the growing and developing basis of life Human fetal development. (a)At 5 weeks, limb buds, eyes, the heart, the liver and rudiments of all other organs have started to develop in the embryo, which is only about 1cm long. (b)Growth and development of the offspring, now called a fetus, continue during the second trimester. This fetus is 14 weeks old and about 6cm long. (c)The fetus in this photograph is 20 weeks old. Now the fetus grows to about 30cm in length. D. The cell is the foundation of reproduce, and the bridge of inheritance. E. Cell (nucleus) is totipotent (全能的), which can create a new organism of the same type As a general rule, the cells of a multicellular organism all contain the same set of genes. For animals, the first evidence that even highly specialized cell carry a full complement of genes was verified by the experiment of tadpole(蝌蚪)nuclei transplanting into unfertilized egg that had been deprived of its own nucleus. Some can develop swimming tadpoles. This is animal cloning. An especially dramatic example of animal cloning was reported in 1997. “Dolly” the first animal ever cloned from a cell derived from an adult. Mammalian cloning. Dolly and her daughter Is there any practical value to such technology? The process of cloning Dolly 哺乳动物的体细胞克隆与细胞全能性 4. Basic properties of cells A. All cells share similar structure, composition and metabolic features ； Plasma membrane, DNA/RNA, and Ribosome. Cells are highly complex and organized, capable of self-regulation; Cells acquire and utilize energy. P21-23 Levels of cellular and molecular organization We can think of complexity in terms of Order and Consistency Self-regulation Left: Normal development of a sea urchin in which a fertilized egg gives rise to a single embryo Right: The cell of an embryo are separated from one another after the first division, and each cell is allowed to develop in isolation and regulating its development to form a complete (although smaller) embryo. Acquiring energy C. Cells can capable of producing of themselves by division. HeLa cells are cultured tumor cells isolated from a cancer patient named Henrietta Lacks in 1951. It is the first human cell to be kept in culture for long periods of time and is still used today. Johns Hopkins univesity,in 1951 D. Cells are able to respond to stimuli via surface receptors that sense changes in the chemical environment. Cells within plant or animal respond to stimuli less obviously than single-celled protist. But they respond. They posses receptors that interact with substances in the environment in highly specific ways. For example, the receptor on the cell surface can respond to hormones and growth factors. E. Cells carry out a variety of chemical reactions and engage in numerous mechanical activities 细胞是多层次非线性的复杂结构体系 细胞具有高度复杂性和组织性 细胞是物质（结构）、能量与信息过程精巧结合的综合体 细胞完成各种化学反应； 细胞需要和利用能量； 细胞参与大量机械活动； 细胞对刺激作出反应； 细胞是高度有序的，具有自组装能力与自组织体系。 细胞能进行自我调控； 繁殖和传留后代； Cells are the basic units of life The basic properties of cells From We can get some new consideration for the conception of cell 生物大分子如何逐级 有序地组装成行使生 命活动的细胞基本结 构体系是个很吸引人 而又相当朦胧的问题 。 因此，细胞的基础研 究势必影响当今生命 科学的整体发展。 Archaebacteria (Archaea) (古细菌-古核生物) Eubacteria (Bacteria) （真细菌） methanogens(产甲烷生物) halophiles(好盐菌) acidophiles(嗜酸菌 ) thermophiles (嗜热菌 ) Sulfolobus（硫化菌） The smallest living cells, the mycoplasma (支原体) (0.2m diameter), which are also the only prokaryotes lacking a cell wall The most complex prokaryotes are the cyanobacteria 5.Types of Prokaryotic Cells: Two Subkingdoms Cyanobacteria Two cells of E. coli during conjugative genetic exchange (x3645). Genetic material moves from the donor to the recipient cell through the clearly visible conjugation tube. 原核细胞的两个代表 A. Subkingdom Archaea B. Subkingdom Bacteria Most Bacteria and Archaea have 1000-4000 genes; The smallest known cells-the Mycoplasma, 0.10.3m; smallest genome: 482 genes, minimal essential gene：256 C. Eukarya Tree of life has three primary branches（or domain） p.23-24 真核细胞可能起源于古细菌的主要证据 （1）细胞壁成分与真核细胞相似，而非由含壁酸的肽聚糖构成。 （2）DNA与基因结构：古细菌DNA中有重复序列的存在。多数古核细胞的基因 组中存在内含子。 （3）有类核小体结构：古细菌具有组蛋白，而且能与DNA构建成类似核小体 结构。 （4）有类似真核细胞的核糖体：多数古细菌类的核糖体较真细菌有增大趋势 ，含有60种以上蛋白，介于真核细胞（7084）与真细菌（55）之间。 抗生素同样不能抑制古核细胞类的核糖体的蛋白质合成。 （5）5S rRNA：根据对5S rRNA的分子进化分析，认为古细菌与真核生物同属 一类，而真细菌却与之差距甚远。5S rRNA二级结构的研究也说明很多古 细菌与真核生物相似。 （6）根据DNA聚合酶分析，氨基酰tRNA合成酶的作用，起始氨基酰tRNA 与肽 链延长因子等分析，也提供了以上类似依据。 p.30 6. Types of eukaryotic cells and structural system Single-celled protists (原生生物) Multicellular organisms-different activities are conducted by different types of specialized cells Differentiation: the process whereby a relatively unspecialized cell becomes a highly specialized cell A. Types of eukaryotic cells: p.31 在个体发育(ontogeny)中,细胞后代在形态结构 和功能上发生差异的过程称为细胞分化。 细胞分化不仅发生在胚胎发育中,而是在一生都 进行着,以补充衰老和死亡的细胞,如:多能造血 干细胞分化为不同血细胞的细胞分化过程。 differentiation B. Three structural systems in Eukaryotes: 1. Bio-Membrane system; 2. Genetic and expression system; 3. Cytoskeleton System. 1 2 3 p.31-32 2 a)Diameter b)Measured in units of micrometers: 1um=10-6 meter nanometers: 1nm=10-9 meter c) Cell size is limited (细胞体积的守恒定律) vsurface area/volume ratio;（反比） vnucleus/cytoplasm ratio;（限制） vSubstances exchange/volume;（限制 ） (substances can efficiently travel through the cytoplasm via diffusion) 7.The Size of Cells p.33-34 Egg is an exception to the rule! p.34 8. Relationship between structure and function of cells l 特化的细胞类型 哺乳动物的红细胞 动物的各类分泌细胞 雌雄生殖细胞等 l正常细胞内部结构（细胞器等） 细胞的形态结构与功能的 相关性与一致性是细胞的共同特点 9. Characteristics that distinguish prokaryotic and eukaryotic cells (1) Complexity: Prokaryotes are relatively simple, eukaryotes are more complex in structure and function p.36 Table 2-2;2-3 The structure of a prokaryotic cell The structure of a Eukaryotic cell (2) Genetic material: All Cells Store Their Hereditary Information in DNA a.Packaging: Prokaryotes have a nucleoid region whereas eukaryote have a true, membrane-bound nucleus. (bacterinm:0.25-3.0 mm, to encode between several hundred and several thousand proteins,The simplest known cells have just under 500 genes). b. Amount: Eukaryotes have several orders of magnitude more genetic material than prokaryotes.(yeast:4.6mm DNA,encoding about 6200 proteins) c. Form: Eukaryotes have many chromosomes that are made of both DNA and protein whereas prokaryotes have a single ,“naked” DNA chromosome (3) Cytoplasm: Eukaryotes have membrane-bound organelles and cytoskeletal proteins; prokaryotes have neither. Both have ribosomes, although they differ in size. (4) Cellular reproduction: Eukaryotes divide by mitosis; prokaryotes divide by simple fission. (5) Locomotion: Eukaryotes use both cytoplasmic movement, and cilia and flagella; prokaryotes have flagella, but they differ in both form and mechanism from eukaryotic flagella. 10. Viruses Virus diversity （1）Viruses are pathogens first described in the late 1800s. （2）Viral structure: - The genetic material: Single- or double- stranded DNA or RNA. - Protein capsid obligatory intracellular parasites. （3）Viral infection types: - Lytic infection; - integrated infection Adenovirus Human Immunodeficiency Virus (HIV) T-e