00:01
In order to answer this question, we have to be able to differentiate between the different mechanisms of transport that exist when we are referring to our plasma membrane.
00:10
So we know that if we look at our plasma membrane, there are going to be different kinds of transport that occur across that membrane.
00:20
We are going to differentiate what type of transport we are using, what mechanism of transport is going to be in use based on the actual.
00:30
Material that we are transporting.
00:32
So if we are going to try to move a small non -polar molecule, well, if there is this concentration gradient working in this direction, well, the small non -polar molecule is actually going to move all the way through.
00:48
So this will occur by simple diffusion.
00:56
So if the concentration gradient is correct, we are going to move from a high concentration to a low concentration if this is a small non -polar molecule by diffusion.
01:06
And then we can also refer to this non -polar molecule as being hydrophobic.
01:15
Now, if we have a large molecule, it may or may not be able to pass through by simple diffusion.
01:31
If it is going to be too large, it might not be able to pass through at all.
01:36
So it will need some sort of help getting across that membrane.
01:42
And if this, once again, the concentration gradient is working in the molecules favor, then it will move from a high concentration to a low concentration via diffusion once again, but in this case it will be facilitated.
01:58
And we say it's facilitated diffusion.
02:02
And i'll explain that in just a moment here, why we say it's facilitated due to this structure right here.
02:14
So this is going to be a channel or a transporter.
02:19
The channel is going to serve as an opening, serves as a gap in the plasma membrane for these larger molecules to pass through...