Lipids are apart of the cell membrane and they are known as phospholipids becuase they have both a polar and an nonpolar side. The head is polar and the body is nonpolar. This keeps the outside of the cell and the cell differentiated. the phospholids tails (the non-polar part) are unsaturdated fattty acids. Unsaturdated fatty acids are chains that are not straights and are slightly bent(kinks) This allows for the cell membrane layer to be fluid
