Fats and lipids are important because they serve as energy source, as well as a storage for energy in the form of fat cells. They also have a major cellular function as structural components in cell membranes. These membranes in association with carbohydrates and proteins regulate the flow of water, ions, and other molecules into and out of the cells. Hormone steroids and prostaglandins are chemical messengers between body tissues. Vitamins A, D, E, and K are lipid soluble and regulate critical biological processes; other lipids add in vitamin absorption and transportation. Lipids act as a shock absorber to protect vital organs and insulate the body from temperature extremes.
Thumbnail: This fluid lipid bilayer cross section is made up entirely of phosphatidylcholine. Image used with permission (Public Domain;).
- Charles Ophardt, Professor Emeritus, Elmhurst College; Virtual Chembook