Which of the following is true for phosphatidylcholine?
Phosphatidylcholine dominates eukaryotic membranes, constituting 40-50% of total phospholipid, existing as zwitterion at neutral pH with positively charged trimethylammonium and negatively charged phosphate, yielding net neutral molecule that stabilizes lamellar bilayer phase and prevents excessive electrostatic repulsion between headgroups. Its cylindrical molecular geometry with roughly equal cross-section of headgroup and two acyl chains favors planar bilayer formation, contrasting cone-shaped PE that induces curvature. Physiologically outstanding example is lung surfactant synthesized by t
Ref: Lodish et al., Molecular Cell Biology, 9th ed., Chapter 10: Phosphatidylcholine and Pulmonary Surfactant.