00:01
To answer this question, we first have to understand what a hydropathy index or hydropathy plot is trying to tell us.
00:09
So the hydropathy index is going to look something like this.
00:17
We have a positive number at the top here, negative at the bottom, have our x -axis here, and the x -axis is telling us the residue number.
00:26
So how far along on that polypeptide chain we are? and it's increasing in this direction.
00:36
So this top portion, anything that's positive, is going to be hydrophobic.
00:45
Whereas below the x -axis is going to be hydrophilic, negative.
00:53
So this is just an orientation that you have to memorize.
00:57
Now, what we see, and for our hydropathy plot that's provided, we see that there's four of these peaks in the hydrophobic.
01:15
Section.
01:17
We ignore the hydrophilic because this is going to be something that is outside of our plasma membrane...