selectively move a particular molecule from one side to the other.

选择性地移动特定分子的例子
What are the properties that we talked about?

我们这里所讲到的特性是什么呢
Membranes are leaky, membranes are leaky because

细胞膜有透过性有透过性的原因是
they have channels, here's a leaky membrane here,

它们具有通道这是一个透过性的细胞膜
and membranes have active transport systems

它具有主动运输系统
that move selectively ions from one side to the other.

能够选择性地将离子从一侧运到另一侧
This is an example that shows how that works with sodium,

这个例子告诉了我们它是怎么作用于钠的
there are systems that work with all of the ions that we've talked about,

我们提过的所有分子都有相应的类似系统
not in exactly the same way but with the same sorts of concepts.

方式不尽相同但概念是一样的
I don't want to say too much about this diagram.

关于这张图表我不想说太多
I just show it here so that you can look at it at your leisure

我只是把它放出来给你们课后看
if that's what you would do with your leisure time.

如果你们课余时间愿意看的话