1离子、小分子物质通过生物膜或磷脂分子的层数离子、小分子物质以跨膜方式(自由扩散、主动运输、协助扩散)通过生物膜。解答此类题目的方法是:明确所研究的物质运动的起点和止点→弄清物质通过的方式和经过的结构及其结构特点→注意一个等量关系“生物膜的层数=1/2磷脂分子的 1 ions, small molecules through the layer of biofilm or phospholipid molecules ions, small molecules in a transmembrane way (free diffusion, active transport, assisted diffusion) through the biofilm. The solution to this type of problem is to specify the starting point and the stopping point of the material motion studied → to find out the way the substance has passed and the structure and structural features it passes through → to pay attention to an isometric relationship. “The number of biofilm layers = 1/2 Phospholipid molecule