Where Species Begin: Structure, Organization and Stability in Biological Membranes and Model Membrane Systems
All living organisms consist of cells, regardless of whether the organism is a simple, single cell bacterium or a highly-evolved mammal containing up to 1012 highly specialized cells performing individualized, well-defined functions. Cell boundaries are defined by cell membranes. These barriers serve to contain and protect cell components from the surroundings as well as regulate the transport of material into and out of the cell. Cell membranes all share a similar bilayer architecture, although the details of membrane composition can vary greatly, from organism to organism and even for different types of cells within the same organism. The origins and purposes of this compositional complexity remain a mystery. This paper examines some of the common denominators shared by (mammalian) cell membranes with particular attention focused on phospholipids, a membrane's primary building blocks. One goal is to emphasize some of the many unresolved questions about how phospholipids organize themselves in cell membranes to provide specific functional behavior and about how slight variation in phospholipid composition affects membrane properties.
- Insights Vol 2 Article 1 (last modified: 16 March 2009)