A triglyceride is a fat. You take in triglycerides anytime you consume plant- or animal-based fats and oils, and you store the triglycerides for later energy use in the fatty tissues of your body. Triglycerides are large molecules that have a distinctive chemical structure.
Elements in Triglycerides
Triglycerides consist entirely of just three elements -- carbon, hydrogen, and oxygen. The molecules of life all have carbon "backbones," meaning the basic shape of the molecule comes from a skeleton of connected carbon atoms. There are always many hydrogen atoms connected to the carbon backbone of a molecule of life -- triglycerides are no exception. There aren't nearly as many oxygen atoms in a triglyceride as there are carbon and hydrogen atoms, but each triglyceride contains a small amount of oxygen.
Structure
Triglycerides have four basic parts -- one glycerol molecule and three fatty acids -- explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry." A glycerol is a three-carbon molecule somewhat similar to an alcohol molecule. The fatty acids are long chains of carbon and hydrogen, with two oxygen atoms at one end. To produce a triglyceride, each of the three fatty acids bonds to the glycerol, producing an almost trident-like structure.
Saturated Triglycerides
Some triglycerides consist of glycerol and saturated fatty acids -- as a result, they're called saturated fats. A saturated fatty acid is one in which there are no double bonds between carbon atoms in the fatty acid carbon tail, explain Drs. Mary Campbell and Shawn Farrell in their book "Biochemistry." Saturated fats have higher melting points than other fats -- they're typically solid at room temperature -- and are most common from animal fat sources.
Unsaturated Triglycerides
If the fatty acids attached to a glycerol molecule have double bonds in their carbon tails, they're called unsaturated fatty acids, and they produce an unsaturated fat. Most plant-based fats are unsaturated. These fats have lower melting points than saturated fats and are therefore liquid at room temperature -- they're oils. They're also generally healthier components of a diet than saturated fat, because they don't contribute to increased blood cholesterol, heart disease and arterial disease.
References
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
- "Biochemistry"; Mary Campbell, Ph.D. and Shawn Farrell, Ph.D.; 2005
