i think you got the idea of this questionbut you used the term "diffuse" wrongly:). ions cannot diffuse through the membrane. "diffuse" means there are no facilitated channels needed and it means the substrate molecules cross the barrier spontaneously.
嘿嘿，不好意思。
其实我在上那门课的时候，一大感觉就是整个一门课一直在吹牛，所有的东西只要吹个差不多就行了。真正理论上的东西老师要求的不是那么严格，感性认识就行。
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