What can a disease like familial hypercholesterolemia tell us about the effects of cholesterol on the people without the disease?

Both functional groups and R-groups attached to the carbon skeletons of biological molecules are important because:

I.      they dictate whether portions of a molecule will be hydrophobic or hydrophilic.

II.     they help determine the amphiphathic character of some lipids

III.    they help determine the tertiary structure of polypeptides.