So we see that there's an Esther bond that exists between the oxygen of this carbon and the carbon of that carboxylic acid, of that fatty acid. And notice that these two fatty acids don't have to be the same exact length. So they can have the same number of carbon atoms or they can be different. And that's why I have M and M. So N can be equal to M, or they can be different integers. Now, what about the third carbon? The third carbon contains an oxygen that is basically attached onto that phosphate component.