Final answer:
A phospholipid molecule consists of a polar, hydrophilic head and nonpolar, hydrophobic tails, making it an amphipathic molecule that contributes to cell membrane structure.
Step-by-step explanation:
The two parts of a phospholipid molecule are the hydrophilic head and the hydrophobic tails. The hydrophilic (water-loving) head is attracted to water and is therefore considered polar. It contains a phosphate group that can interact with water.
The hydrophobic (water-fearing) tails are repelled by water and are nonpolar. These tails are made up of two fatty acid chains that avoid water and prefer to face towards each other.
Phospholipids are amphipathic molecules, meaning they have both a hydrophilic and hydrophobic part, which allows them to form bilayers that make up cell membranes, with the heads facing the aqueous environments both outside and inside the cell while the tails face each other, creating a barrier that separates these environments.