The Basic Structure and Dynamics of Cell Membranes: An Update of the Singer-Nicolson Model

Biochim Biophys Acta. 2014 Jun;1838(6):1467-76. doi: 10.1016/j.bbamem.2014.01.006. Epub 2014 Jan 16.


The fluid mosaic model of Singer and Nicolson (1972) is a commonly used representation of the cell membrane structure and dynamics. However a number of features, the result of four decades of research, must be incorporated to obtain a valid, contemporary version of the model. Among the novel aspects to be considered are: (i) the high density of proteins in the bilayer, that makes the bilayer a molecularly "crowded" space, with important physiological consequences; (ii) the proteins that bind the membranes on a temporary basis, thus establishing a continuum between the purely soluble proteins, never in contact with membranes, and those who cannot exist unless bilayer-bound; (iii) the progress in our knowledge of lipid phases, the putative presence of non-lamellar intermediates in membranes, and the role of membrane curvature and its relation to lipid geometry, (iv) the existence of lateral heterogeneity (domain formation) in cell membranes, including the transient microdomains known as rafts, and (v) the possibility of transient and localized transbilayer (flip-flop) lipid motion. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.

Keywords: Cell membrane; Membrane dynamics; Membrane structure; Singer–Nicolson model.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Membrane Structures / chemistry*
  • Cell Membrane Structures / metabolism*
  • Cell Physiological Phenomena*
  • Humans
  • Membrane Lipids / chemistry*
  • Membrane Lipids / metabolism
  • Membrane Proteins / chemistry*
  • Membrane Proteins / metabolism
  • Models, Biological


  • Membrane Lipids
  • Membrane Proteins