《分子细胞生物学》 Chapter 4 Cell Membrane and Cell Surface

Chapter 4: Cell Membrane and Cell Surface I. Cell membrane I. Cell Junctions II. Cell adhesion IV. Extracellular matrix http://www.cbi.pku.edu.cn/chinese/documents/chenjg

Chapter 4: Cell Membrane and Cell Surface I. Cell Membrane II. Cell Junctions III. Cell Adhesion IV. Extracellular Matrix http://www.cbi.pku.edu.cn/chinese/documents/chenjg/

I Biomembranes: Their Structure Chemistry and functions Learning obiectives: a brief history of studies on the structrure of the plasma membrane 2. Model of membrane structure: an experimental perspective 3. The chemical composition of membranes 4. Characteristics of biomembrane 5. An overview of the functions of biomembranes

I. Biomembranes: Their Structure, Chemistry and Functions Learning objectives: 1. A brief history of studies on the structrure of the plasma membrane 2. Model of membrane structure: an experimental perspective 3. The chemical composition of membranes 4. Characteristics of biomembrane 5. An overview of the functions of biomembranes

(Boundary and permeability barner● Organization and localization of function Nucleus (5) Cell-to-cell communication (3 Transport processes ◎ Nutrients (4) Signal detection

1. 1. A brief history of studies on the structrure of the plasmic membrane 的计论 A. Conception: Davson an 路poen Plasma membrane(cell membrane), Intracellular membrane, Biomembrane Robertson B. The history of study nwn and ◇ Overton(1890s Lipid nature of PM

1. 1. A brief history of studies on the structrure of the plasmic membrane A. Conception: Plasma membrane(cell membrane), Intracellular membrane, Biomembrane. B. The history of study Overton(1890s): Lipid nature of PM;

◆ J.D. Robertson(1959) The TEM showing the trilaminar appearance of PM Unit membrane model: oS.J. Singer and GNicolson(1972) fluid-mosaic model ◆ K. Simons et a(1997) lipid rafts model Functional rafts in Cell membranes Nature387:569-572 Figure 44 A bref hisory ef the strudhair of the plasma face ef mo moran pretests sell saul that enterd tough the L pid. singer and Niade in ef wss pe lipid e sciene 1732724.14 lunn Papn 28. pete nt peewee from s I sewer an G, L Noodie Anmtcenmte nee c Inn D Varl aL G val,Ba tr wRn& Soes. lee)

 J.D.Robertson(1959): The TEM showing:the trilaminar appearance of PM; Unit membrane model;  S.J.Singer and G.Nicolson(1972): fluid-mosaic model;  K.Simons et al(1997): lipid rafts model; Functional rafts in Cell membranes. Nature 387:569-572

2. Singer and Nicolson's Model of membrane structure: The fluid-mosaic model is the " central dogma" of membrane biology. A. The core lipid bilayer exists in a fluid state, capable of dynamic movement B Membrane proteins form a mosaic of particles penetrating the lipid to varying degrees. (outside of cell membrane protein The fluid mosaic glycoprotein Model, proposed in cholesterol 1972 by Singer and phospholipid Nicolson had two key features, both 。 implied in its name (cytoplasm inside of cell

2. Singer and Nicolson’s Model of membrane structure: The fluid-mosaic model is the “central dogma” of membrane biology. A. The core lipid bilayer exists in a fluid state, capable of dynamic movement. B. Membrane proteins form a mosaic of particles penetrating the lipid to varying degrees. The Fluid Mosaic Model, proposed in 1972 by Singer and Nicolson, had two key features, both implied in its name

CHOLINE PrICHA polar hydrophilic) PHOSPHATE head group GLYCEROL CH: CH, N CH CH nonpolar cs.doubk (hydrophobic band tails Figure 10-2. The parts of a phospholipid molecule. Phosphatidylcholine, represented schematically(a), in formula(b),as a space-filling model( c), and as a symbol (). The kink due to the cis double bond is exaggerated in these drawings for emphasis

Figure 10-2. The parts of a phospholipid molecule. Phosphatidylcholine, represented schematically (A), in formula (B), as a space-filling model (C), and as a symbol (D). The kink due to the cis￾double bond is exaggerated in these drawings for emphasis

3. The chemical composition of membranes A. Membrane Lipids: The Fluid Part of the model x Membrane lipids are amphipathic. .There are three major classes of lipids: Phospholipids: Phosphoglyceride and sphingolipids Glycolipids Sterols( is only found in animals)

3. The chemical composition of membranes A. Membrane Lipids: The Fluid Part of the Model Phospholipids: Phosphoglyceride and sphingolipids Glycolipids Sterols ( is only found in animals) ❖Membrane lipids are amphipathic. ❖There are three major classes of lipids:

崇 micelle water 00000000 bayer 0000004 Figure 10-3. a lipid micelle and a lipid bilayer seen in cross-section. Lipid molecules form such structures spontaneously in water. The shape of the lipid molecule determines which of these structures is formed Wedge-Shaped lipid molecules(above) form micelles, whereas cylinder shaped phospholipid molecules(below) form bilayers

Figure 10-3. A lipid micelle and a lipid bilayer seen in cross-section. Lipid molecules form such structures spontaneously in water. The shape of the lipid molecule determines which of these structures is formed. Wedge-shaped lipid molecules (above) form micelles, whereas cylinder￾shaped phospholipid molecules (below) form bilayers