Phospholipids:

Phospholipds are molecules that consist of a hydrophilic ("water loving") head group connected to a hydrophobic ("water fearing") tail. The phospholipid shown at the left is phosphotidyl ethanolamine. It consists of two long chain fatty acids (the two long gray tails at the bottom of the molecule; the two red spheres at the top of the tails represent the carboxylic acid moieties) linked to a molecule of glycerol (at the top of the tails). The glycerol is then linked through a phosphate (the yellow sphere, phosphorus, surrounded by four red spheres, oxygen) to a molecule of ethanolamine. Here is a conventional drawing of the structure:

the R1 and R2 groups refer to the fatty acids that are attached to the glycerol molecule.