Answer:
Because they are normally dissolved in water
Step-by-step explanation:
The phospholipids can act as molecules that are carry inside or outside the cells, to transport it they are dissolved in another hydrophilic media, in this way the hydrophilic part can be in the outside part of the group of moleucles stick together like in cell membranes that are conformed by a double lipidic layer, in which the hydrophobic part it in the inside part. The cells normally are surrounded by different water solutions as the blood or another solutions.