被动转运Passive Transport The movement of substances across the membrane by down their concentration or electrochemical gradient without consumption of energy. 指物质顺电位或化学梯度通过细胞膜的转 运过程，不需消耗能量 分类： simple diffusion(单纯扩散) facilitated diffusion（易化扩散) 被动转运 Passive Transport The movement of substances across the membrane by down their concentration or electrochemical gradient without consumption of energy. 指物质顺电位或化学梯度通过细胞膜的转 运过程,不需消耗能量 分类: simple diffusion(单纯扩散) facilitated diffusion (易化扩散)