In this module:

Phospholipids

If one of the fatty acids in a glycerolipid is replaced by a hydrophilic group containing phosphorus, the result is a phospholipid .

Click on the structure to see different polar phosphorus-containing groups commonly found in phospholipids.

What do hydrophobic
and polar mean?

The cartoon below the structures shows a common way of representing phospholipids. Because in the cartoon, the polar phosphorus-containing group looks like a head, it is often called a headgroup. Because the hydrophobic hydrocarbon groups look like tails, they are often called the hydrophobic tails. The important thing to note is that a phospholipid has both a hydrophobic and a polar part, giving it special properties that the cell takes advantage of. Molecules with both a hydrophobic and a polar part are called amphiphiles .