Phospholipids

Figure 1. Phospolipids forming the lipid bilayer in cell membranes.

Phospholipids are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group, which can be modified with simple molecules such as Choline, and two hydrophobic "tails" derived from fatty acids. Marine Phospholipids such as those found in fish typically have Omega-3 fatty acids Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) in their tails. Phospholipids are also a component of Lecithin.

Phospholipids are a key component of all cell membranes, forming lipid bilayers due to their amphiphilic characteristic (i.e. soluble both in water and lipid). The cell's membrane consists of two layers of oppositely oriented phospholipid molecules, with their heads exposed on both sides and their tails directed into the membrane. This is the dominant structural pattern cell membranes and some other biological structures. The lipid bilayer acts as a gate by controlling the types of compounds that are allowed through the membrane and within the membrane.

Phospholipids are available as a dietary supplement. Taken as a supplement, Phospholipids are often promoted for the same benefits as fatty acids such as to maintain the health of nervous systems and normal brain functioning.