复旦大学生理学课件01生物膜对物质的通透和转运

1、第一篇 细胞生理学 第一章 生物膜的物质转运功能 第二章 细胞的兴奋 第三章 细胞间信息传递 第四章 肌细胞的收缩功能第一章 生物膜的物质转运功能from Berne & Levy Principles of Physiology (4th ed) 2005Chap. 1 Cellular Membranes and Trans-membrane Transport of Solutes and Water Cell membrane serves as a permeability barrier that allows the cell to maintain a cytoplasmic

2、composition far different from the composition of the extracellular fluid. The membranes that enclose the various organelles divide the cell into discrete compartments and allow the localization of particular biochemical processes in specific organelles. Singer 流动镶嵌模型Simple Diffusionvia carriers Fac

3、ilitated DiffusionSaturation: as the concentration of the transported compound is increased, the rate of transport at first increases, but eventually a concentrations reached after which the transport rate increases no further.Specificity: only molecules with the requisite chemical structure are tra

4、nsported.Competitive inhibition: structurally related molecules may compete for transport. water channelion channels叶公杼和詹裕农Shaker钾通道Ionic selectivity:Activation:voltage-gated, ligand-gated, mechanosensitive or background current channel离子通道的随机活动 primary active transport has a direct link to metaboli

5、c energy, via pumps. Active Transport secondary active transport derives energy from the concentration gradient of another substance that is actively transported, via symporter or antiporter (exchanger).钠钾泵细胞的钙转运系统 Endocytosis and Exocytosisreceptor mediated endocytosisphagocytosisfluid phaseendocytosis simple diffusion primary active transport endocytosis & exocytosis facilitated diffusionporesion