Summary
Lipids with a hydrophilic phosphate head and two hydrophobic tails that self-assemble into membranes.
In depth
A glycerol backbone carries two fatty acids and a phosphate group linked to a polar group such as choline. These amphipathic molecules form bilayers, micelles and liposomes in water.
They are the main membrane lipids and provide a basis for drug delivery in liposomes and lipid nanoparticles.
Phospholipids vary by head group: phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol each have roles; the last is phosphorylated to make signalling molecules such as PIP2 and PIP3. Lecithin is a mixture rich in phosphatidylcholine used as an emulsifier in foods.
The pulmonary surfactant is a phospholipid mixture that lowers surface tension in alveoli; premature babies lacking it develop respiratory distress syndrome. Sphingolipids, such as sphingomyelin, form the myelin sheath that insulates nerves.
Remember: amphipathic means having both a water-loving part and a water-fearing part, which is the key property.
Frequently asked questions
What is Phospholipids?
Lipids with a hydrophilic phosphate head and two hydrophobic tails that self-assemble into membranes.
Which area of biology covers Phospholipids, and how advanced is it?
Phospholipids is one of the 51 topics in Biomolecules & Biochemistry. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Lipids, Water Properties, Lipid Rafts.
Can you give an example of Phospholipids?
MRNA vaccines use lipid nanoparticles to carry mRNA into cells.
What should I learn before Phospholipids?
Work through the Beginner topics in Biomolecules & Biochemistry first, such as Water Properties, Carbon Chemistry, Carbohydrates, then return to Phospholipids. Intermediate topics assume the Beginner vocabulary.
What topics are related to Phospholipids?
The closest topics to Phospholipids are Lipids, Water Properties, Lipid Rafts, Triglycerides. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Phospholipids?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Phospholipids. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
How is Phospholipids different from Lipids?
Phospholipids: Lipids with a hydrophilic phosphate head and two hydrophobic tails that self-assemble into membranes. Lipids: Hydrophobic molecules including fats, oils, waxes and steroids used for energy storage, insulation and membranes. Read both side by side and note what each one explains.
How should I study Phospholipids step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Lipids and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.