Why Is the Cell Membrane Asymmetric?

💡 The Answer

• The inner leaflet is enriched in phosphatidylserine and phosphatidylethanolamine, which are important for signaling.
• The outer leaflet contains more sphingomyelin and glycolipids, contributing to recognition and protection.
• This asymmetry is actively maintained by flippases that move lipids between leaflets.
• Disruption of asymmetry, such as phosphatidylserine exposure to the outer leaflet, triggers apoptosis and clearance.