Lipids are found in the cell membrane of a cell, Specifically phospholipids.
It is made up of 3 parts: A phosphate head and 2 fatty acids. The phosphate head is hydrophilic (likes water), that's why its on the outer sides of the membrane, and the 2 fatty acids are hydrophobic (hate water), thats why they are on the inner sides of the membrane so they dont have any contact with water. (In the picture above, the red balls are the phosphate heads and the 2 yellow strings joined to each ball are the fatty acids)
