FIGURE 1.

The fluid mosaic and patchwork quilt models of the cell membrane: The Singer Nicholson model of the membrane where proteins are dissolved in a two‐dimensional fluid sea of lipids (top), has given rise over the years to a more variegated view of the membrane where the membrane is today considered as a patchwork quilt of multiple domains of proteins and lipids of a variety of compositions (middle and bottom). These models are predominantly based on thermodynamic equilibrium principles, and embody an equilibrium steady state expectation of this complex mixture of proteins and lipids. The light brown and other multicolored balls represent different lipid head group species that populate the membrane. Transmembrane proteins are shown as green blobs that traverse the membrane bilayer and dark brown proteins denote various kinds of extrinsic surface proteins. Note how various proteins are associated with subsets of multicolored lipid species (middle and bottom panel) while membrane lipids are also thought to form a patchwork quilt (bottom panel). The extracellular matrix is shown as a cross‐linked network of blue filaments, and the cytoskeletal elements are detailed as red filaments