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 Chap. 1 Cellular Membranes and Trans-membrane Transport of Solutes and Water from Berne & Levy Principles of Physiology (4th ed) 2005
Cell membrane serves as a permeability barrier that allows the cell to maintain a cytoplasmic 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 Diffusion
Facilitated Diffusion via carriers
Specificity: only molecules with the requisite chemical structure are transported. Saturation: 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. Competitive inhibition: structurally related molecules may compete for transport.
water channel
ion 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
Active Transport primary active transport has a direct link to metabolic energy, via pumps. 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 Exocytosis fluid phase endocytosis receptor mediated endocytosis phagocytosis
through simple diffusion passive pores ion channels carriers facilitated diffusion primary active transport active symport antiport secondary active transport endocytosis & exocytosis across