A phospholipid molecule has a polar end, which is hydrophilic (water-loving), and a nonpolar end, which is hydrophobic (water-hating). Water molecules are polar molecules, meaning they have a positive end and a negative end. The positive end of a water molecule is attracted to the negative end of a phospholipid molecule, and the negative end of a water molecule is attracted to the positive end of a phospholipid molecule. This attraction is what causes water molecules to form hydrogen bonds with phospholipid molecules.