PHOSPHOLIPIDS

• Most abundant lipid present in cell membrane, also called membrane lipid.
• It is made up of lipid & phosphoric acid.
• The basic phospholipid is phosphatidic acid.
• They are respectively known as phosphatidylcholine (lecithin), phosphatidylethanolamine (cephalin), phosphatidylserine and phosphatidylinositol.
• Phospholipids are amphipathic having both hydrophobic and hydrophilic ends.
• Phospholipids also account for fluidity and selective permeability of membranes.
• Lecithin acts as a carrier molecule, by its deficiency fatty liver disease is caused.
• Cephalin present in egg yolk, nervous tissue.
• Cephalin helpful in blood clotting.
• Plasmogens present in brain & myelin sheath.
• Sphingomyelin is a phospholipid, which do not contain glycerol.
• Sphingosine is found, eg. nervous tissue.
• Sphingomyelins occur in most animal membranes.
• They are also present in good quantity in myelin sheath of nerve fibres.