Facilitated Diffusion(易化扩散 The diffusion of water-soluble substances through the cell membrane down the concentration gradient with the aid of particular membrane transport proteins. 水溶性物质借助特定蛋白质的帮助顺浓度梯度通过细胞膜的 转运方式 Transported Uniport molecules Carrier Channel molecule 1Channel mediated diffusion 经通道的易化扩散 2carrier mediated diffusion 经载体的易化扩散 Simple diffusion Facilitated diffusion Passive transport
Facilitated Diffusion (易化扩散) ②carrier mediated diffusion 经载体的易化扩散 ①Channel mediated diffusion 经通道的易化扩散 The diffusion of water-soluble substances through the cell membrane down the concentration gradient with the aid of particular membrane transport proteins. 水溶性物质借助特定蛋白质的帮助顺浓度梯度通过细胞膜的 转运方式
Channel mediated diffusion characteristic 话Na。>Na ①selectivity 膜外 选择性 通道 ②high velocity K门：>K]。 高速率 膜内
[K+] i ＞[K+]o [Na+]o ＞[Na+] i Channel mediated diffusion characteristic ①selectivity 选择性 ②high velocity 高速率
Membrane channels ONa Open Closed © 0 FIGURE 3-14 Membrane channels.Gated channel proteins form tunnels through which specific molecules may pass-as long as the "gates"are open.Notice that the transported molecules move from an area of high concentration to an area of low concentration
Types of channel 1chemical-gated channel (化学门控通道) 2Voltage-gated channel 电压门控通道) 3mechanical gated channel) (机械门控通道)
Types of channel ①chemical-gated channel (化学门控通道) ②Voltage-gated channel (电压门控通道) ③mechanical – gated channel) (机械门控通道)
Carrier Mediated Diffusion Characteristics: ①specificity (特异性) 载体蛋白质 膜外 2competitive inhibition (竞争性抑制) 扬延女勤勤必业越步沙 ③saturation (饱和现象) 膜内
Carrier Mediated Diffusion Characteristics: ①specificity (特异性) ②competitive inhibition (竞争性抑制) ③saturation (饱和现象)