However, when that gate is opened, the sodium channel is now going to be incredibly selective and only let through sodium ions and no other type of ion.
但是,当闸门打开的时候,钠离子通道,将会有极高的选择性,不允许除钠离子以外的任何其它离子通过。
many of these ion channels have this size exclusion pore, it's a very important part of them.
很多离子通道也都有这样的具有尺寸排斥性的小孔,这是它们非常重要的组成部分。
It can exist in - a gated ion channel - can exist in one or two states.
它们能够存在于,门控离子通道有一种或者两种状态
And when we talk about any type of ion channel, there are just tons of different kinds of ion channels, and you can characterize them in a few different ways.
而当我们讨论任何一种离子通道时,离子通道有非常多种,你可以用几种不同的方法来描述它们。
So the influx of ions from the outside of the cell to the inside of And you can think of ion channels as being gated, by gated it means the gate can be closed and no ions are going through, as in this case here.
下面以离子从细胞外部流入内部,你可以把离子通道想象成是有闸门的,也就是说闸门可以关上,这时没有离子能通过,就像这种情况。
It has a gate on it and that gate is in open or close state depending on whether a ligand is present or not.
在这个通道上有个门,这个门是打开还是关闭,取决于配体到来与否
All cell membranes have these channels within them, and under their resting conditions sodium is moving from outside to inside, potassium's moving from inside to outside.
所有细胞膜上都有这种通道结构,在静息状态下,钠从细胞外流向细胞内,钾从细胞内流向细胞外
A state where it's closed, so imagine a channel with a lid on top of it; when it's closed nothing can go through the channel, when it's open then things can go through.
一种是闭合状态,想想一个有盖子的通道吧,当盖子合上的时候任何东西都不能通过,而打开时就畅通无阻
Now, remember we talked about these last time, voltage-gated channels are channels that would allow the passage of sodium, in this case, but they can exist in two states, a closed state and an open state.
还记得我们上节课讨论过的吧,电压门控通道是,一种可以容许钠离子通过的通道,在这一例子中 电压门控通道有两种状态,关闭状态和开放状态
Now, it's more complicated than that because it's not just sodium channels that are involved, there are potassium channels also, and the interplay between sodium channels opening and potassium channels opening, this is described in some detail in your book.
现在 事情更复杂了,因为这一过程不仅关系着钠离子通道,也关系着钾离子通道,以及钠离子通道和钾离子通道之间开关,的相互作用,书中有详细解释
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