Phospholipids comprise an important class of biological molecules that serve both structural and functional roles in the human body. Their unique composition allows phospholipids to form isolated "envelopes" within the watery environment of your body, and they can be used by your cells as raw material for other essential processes.
As its name implies, a phospholipid consists of a phosphate portion – a phosphorus atom attached to a vitamin, amino acid or other molecule – and a lipid, or fat-like, portion. The phosphate "head" of a phospholipid molecule is capable of mixing with water – it is said to be "hydrophilic" – while the lipid "tail" is incapable of mixing with water, thus making it "hydrophobic." Due to the presence of two such dissimilar appendages on the same compound, chemists call phospholipids "amphipathic," a property that is essential for the continued existence of every cell in your body.
According to scientists at the City University of New York, phospholipids can form a variety of structures when they are suspended in water. As these amphipathic molecules arrange themselves within an aqueous environment, they can congregate into solid spheres – their hydrophilic heads pointing outward and their hydrophobic tails directed inward – or spread out into sandwich-like sheets called bilayers. Phospholipid bilayers can themselves form hollow, water-containing spheres, thus providing the basic foundation for all living cells and many of the structures they contain, such as lysosomes, mitochondria and nuclei.
Like many other lipid-containing molecules, phospholipids can be broken down in your body and utilized for energy. In addition, a study published in the June 2006 issue of "Journal of Leukocyte Biology" demonstrated that phospholipids can be split by enzymes to form signaling molecules called chemokines, which are instrumental in regulating cellular migration, enzyme production and many other cellular processes. One phospholipid that is both structural and functional is sphingomyelin, which forms the insulation that protects your nerves and facilitates the conduction of nerve impulses.
As a class, phospholipids are one of the most important molecules in your body. They provide the bilayered envelopes that make cells possible, and they serve in a variety of other structural and functional roles. Phospholipid synthesis is accomplished within your cells from simpler precursors that are derived from your diet. B vitamins, such as inositol and choline, amino acids from proteins and essential fatty acids are all needed for phospholipid production. A well-balanced diet is the best way to ensure adequate nutrients for phospholipid synthesis.