The plasma membrane was first conceptualized by Carl Wilhelm Nägeli and C. Cramer in 1855. The modern Fluid Mosaic Model was proposed by S.J. Singer and Garth Nicolson in 1972.
- Nägeli (1855): Proposed a boundary membrane based on osmotic behavior
- Overton (1899): Proposed the membrane is lipid-based
- Singer & Nicolson (1972): Proposed the Fluid Mosaic Model a phospholipid bilayer embedded with freely moving proteins
Structure of the plasma membrane:
- Phospholipid bilayer (hydrophilic heads outward, hydrophobic tails inward)
- Embedded proteins (integral and peripheral)
- Cholesterol molecules (in animal cells, for stability)