The Function of Lipids: An In-depth Explanation of These Fats

We often associate the term "lipids" with the term "fats." In some ways that association is correct, in others it's wrong. The evil that comes from defining the term "lipids" as "fats" is that we tend to think of fats as bad things. Thus lipids are bad, and really they aren't bad at all. While lipids are classified as a group of "fats," not all lipids are fats; and all lipids perform essential body functions. In fact, we need lipids to survive and function on a normal everyday basis. Perhaps instead of group defining the term "lipids" we should more closely at what exactly it is that lipids do within the body.

There are several different forms of lipids in the body, and each serve a specific and very important purpose. The first group of lipids is a group devoted to the storage of energy. When we think energy we often think carbohydrates, and while it is true that carbohydrates provide energy for the body, it is the lipids which play an essential role in storing that energy for a later time. Lipids are able to store more energy per gram of their mass than carbohydrates and protein. (Ophardt, 2003). Without lipids, we wouldn't have enough energy to do more than an hour of activity!

Aside from storing energy, lipids also form the membrane of body cells. The membrane, also known as the plasma membrane, is made up of a bilayer of lipids. This lipid layer serves as a means of keeping bad things from entering the cell and is what is referred to as "semi-permeable," which means it can select what enter and what doesn't. Additionally, the lipid bilayer membrane serves to hold the cell together and keep organelles safely inside the cell. Additionally, the cell membrane serves to recognize necessary enzymes, transports food sources into the cell, and contains specific sites for hormone recognition. (Purves, Sadava, Orians, and Heller, 2001).

On that same note, lipids and lipid derivatives are used as hormones and vitamins. (King, 2006). Hormones act as chemical messengers to the body, and lipid hormones play a huge role in regulating metabolism. (Layman, 2003) Additionally, the sex hormone testosterone that is predominately in males, but excreted in small amounts by woman, is another lipid based hormone. As such, lack of lipids in the body can result in reduced deterred sexual maturation or sexual health.
With all these important functions, it is easy to see why lipids are an extremely essential part of our bodies. It is easy to see why doctors and scientists say that we need fats in our bodies to survive. Without lipids our energy levels would be almost non-existent, our cells would be fragile and unable to keep good substances in and bad substances out, and our hormones would be completely out of order. Clearly, our bodies simply can't do without lipids.

References:

WKU. (n.d). Lipids. Retrieved April 17, 2007, from WKU Bio 113 Website: http://bioweb.wku.edu/courses/biol115/Wyatt/Biochem/Lipid/lipid1.htm

Layman, D. PhD. (2003). Biology Demystified. McGraw Hill Publishing. New York, NY. (pg. 61).

King, M. PhD. (2006). Role of Biological Lipids. Retrieved April 17, 2007, from IU School of Medicine Website:http://web.indstate.edu/thcme/mwking/lipids.html

Ophardt, C. E. (2003). Overview of Lipid Function. Retrieved April 17, 2007, from Virtual Chembook Elmhurst College Website: http://www.elmhurst.edu/~chm/vchembook/620fattyacid.html

Purves, Sadava, Orians and Heller. (2001). Life the Science of Biology 6^th Edition, Sinauer/Freeman Publishing Co. Viewed at:

http://www.sci.sdsu.edu/classes/biology/bio202/TFrey/MembraneStructure.html