What does phospholipid mean?
A phospholipid is a complex lipid, meaning a lipid that includes a phosphate group. These molecules are amphipathic: each has a polar head that interacts with water and hydrophobic tails that avoid it. In water, phospholipids spontaneously arrange into bilayers, creating the thin, flexible barriers that define cell membranes and many membrane-bound compartments. They also participate in cell signaling, transport, and the structure and function of lipoproteins; certain phospholipids also act as natural surfactants. The term is therefore most common in biochemistry, medicine, and food science rather than general conversation. In nutritional and health contexts, “phospholipids” may refer to a group of compounds sold as ingredients or supplements, without implying that they are interchangeable or equally well absorbed. The word is useful because it names a structural class rather than one single substance, revealing how simple chemical principles combine to make cellular life possible.
nounA phospholipid is any member of a class of complex lipids containing a phosphate group. Its molecules typically have a polar, water-attracting head and one or more hydrophobic tails, allowing them to form biological membranes.
- A complex lipid containing a phosphate group, typically with a polar head and hydrophobic tails; phospholipids form the structural framework of biological membranes.
"The phospholipid molecules aligned with their heads facing water and their tails facing inward, forming a stable membrane."
"The phospholipid molecules aligned with their heads facing water and their tails facing inward, forming a stable membrane."
"Food scientists may add phospholipids such as lecithin to improve texture and keep fat and water mixed."
Use the plural when referring to multiple molecules or to members of the class collectively.
"Phospholipids are arranged in two layers across the cell membrane."
A phospholipid bilayer is only a few nanometres thick, yet it gives every cell a selective boundary between itself and the world outside.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does phospholipid come from?
Phospholipid was formed by combining phospho- with lipid, a word based on Greek lipos, meaning “fat.” The phospho- element comes through phosphorus, a Latin borrowing of Greek phōsphoros, “light-bearer,” from phōs, “light,” and phoros, “bearing.” Its development reflects the growth of biochemical terminology during the early study of complex lipids.
Related word forms
How phospholipid is actually used
This is primarily formal scientific vocabulary used in biochemistry, medicine, nutrition, and food science rather than everyday speech. It may refer either to an individual molecule or generically to the class of compounds.
Easily confused with phospholipid
A phosphate is a phosphorus- and oxygen-containing ion or salt, whereas a phospholipid is a complex lipid that includes a phosphate group within a larger membrane-forming molecule.