The organic chemicals that help cell membranes to conserve internal fluids are the phospholipids. They are composed of fatty acid, glycerol, phosphate group and a polar molecule. The phosphate group and polar head region of the phospholipids is attracted to water while the fatty acid is repelled by water. They are a major component of the cell membrane in which it encloses the organelles of the cell. It also limits what enters and exits the cell because of its two heads.