Phosphatidylethanolamine and Related Lipids

Phosphatidylethanolamine (once given the trivial name ‘cephalin’) is usually the second most abundant phospholipid in animal and plant lipids and it is frequently the main lipid component of microbial membranes. It can amount to 20% of liver phospholipids and as much as 45% of those of brain; higher proportions are found in mitochondria than in other organelles. As such, it is obviously a key building block of membrane bilayers. It is a neutral or zwitterionic phospholipid (at least in the pH range 2 to 7) with the structure shown (with one specific molecular species illustrated as an example).