What are lipids made of

Lipids are a large and diverse group of naturally-occurring organic compounds that are primarily made of carbon, hydrogen and oxygen. Some lipid molecules may also contain phosphorus, nitrogen, and sulfur. Although there is great structural variety among lipids, they are all related by their general insolubility in water and solubility in nonpolar organic solvents such as benzene, ether, and chloroform. This is because of the presence of nonpolar carbon-hydrogen bonds. The 4 biologically important lipids are fats, phospholipids, waxes and steroids. 

1. Fats are large molecules composed of 3 long-chain fatty acid molecules bonded to a glycerol molecule. 
2. Phospholipids are the main structural components of the cell membrane. They are composed of 2 fatty acid chains bonded to a glycerol molecule. They also contain the element phosphorus. Phospholipids are unique from other lipids in that they have a hydrophobic end and a hydrophilic end. 
3. Waxes are composed of only 1 long-chain fatty acid bonded to a long-chain alcohol group. Waxes are extremely hydrophobic. Their lack of affinity for water is because of their long nonpolar carbon chains.  
4. Steroids have a completely different structure from that of other lipids. They have a fused ring structure in which the carbon skeleton is bent, forming 4 fused rings each containing 5 or 6 carbons.