- Provide energy
- Primary form of energy storage in the body
- Insulate and protect
- Aid in the absorption and transport of fat-soluble vitamins.
A triglyceride is formed by three fatty acids being bonded to glycerol as shown below.
When a fatty acid is added to the glycerol backbone, this process is called esterification. This process is so named, because it forms an ester bond between each fatty acid and the glycerol. Three molecules of water are also formed during this process as shown below.
A stereospecific numbering (sn) system is used to number the three fatty acids in a triglyceride sn-1, sn-2, and sn-3 respectively. A triglyceride can also be simply represented as a polar (hydrophilic) head, with 3 nonpolar (hydrophobic) tails, as shown below.
The three fatty acids in a triglyceride can be the same or can each be a different fatty acid. A triglyceride containing different fatty acids is known as a mixed triglyceride. An example of a mixed triglyceride is shown below.