In which year was the fluid mosaic model proposed by Singer and Nicolson? The model commonly represented cell membrane structure and dynamics.

The correct answer is 1972.

Key Points

• The fluid mosaic model was proposed by S.J. Singer and G.L. Nicolson in 1972.
• This model describes the structure of cell membranes as a mosaic of components that gives the membrane a fluid character.
• It emphasizes that the cell membrane is flexible and constantly in motion, rather than being static.
• The model was revolutionary for illustrating the dynamic nature of the lipid bilayer and the embedded proteins.

Additional Information

• Lipid Bilayer:
  • A double layer of lipids that forms the core structure of the cell membrane.
  • Each lipid molecule has a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails.
• Integral Proteins:
  • Proteins that are embedded within the lipid bilayer.
  • They can span the entire membrane (transmembrane proteins) or be attached to only one side.
• Peripheral Proteins:
  • Proteins that are attached to the exterior or interior surfaces of the lipid bilayer.
  • They are not embedded within the lipid bilayer.
• Fluidity:
  • Refers to the viscous nature of the lipid bilayer, allowing lateral movement of molecules within the layer.
  • Fluidity is influenced by temperature and the composition of the lipid molecules.
• Mosaic Nature:
  • Describes the heterogeneous composition of the cell membrane, including lipids, proteins, and carbohydrates.
  • These components are not uniformly distributed, contributing to the diverse functionality of the cell membrane.