2.5 chemical elements

Lipids (fats and oil)
-Carbon Hydrogen Oxygen
Structure: 
fats-animals
oils-plants

Carbohydrates
- Carbon Hydrogen Oxygen
Structure:
Simple molecules-->sugars
Larger Molecules -->Polysaccharides/starch

Proteins
- Carbon Hydrogen Oxygen Nitrogen
Structure
Simple: Amino acids
Larger: Proteins