Sterols:

Sterols are molecules that consist of a hydrophilic ("water loving") and hydrophobic ("water fearing") portions. The sterol shown at the left is dehydroisoandrosterone, a sterol common in human blood. Sterols consist of a set of fused carbon rings, three with six carbons and one with five. These are the hydrophobic part of the molecule. The rings are decorated with other groups, for example hydroxyl groups (–OH represented by a red sphere in the picture on the left, oxygen). These groups are more hydrophilic.

Here is a drawing of the sterol ring structure: