Covalent bond is indicated by the arrow.
A phospholipid is made of glycerol, two the fatty acid tails, and a phosphate-linked head group. More unsaturated fatty acids it means less tightly packed phospholipids its results to the greater membrane fluidity. Unsaturated fatty acids are naturally occurring, meaning that the remaining hydrogen is on the same side of the molecule and result in a bending of the hydrocarbon chain.
