Summary:
- A lipid is an organic compound such as fat or oil.
- Organisms use lipids to store energy, but lipids have other important roles as well.
- Lipids consist of repeating units called fatty acids.
- Fatty acids are organic compounds that have the general formula CH3(CH2)nCOOH.
- There are two types of fatty acids: saturated fatty acids and unsaturated fatty acid.
- Unsaturated fatty acids have bent chains, like all the other fatty acids in the figure.
- Excess dietary lipids can be harmful because they are high in energy.