Fluid mosaic model:
(i) Fluid mosaic model was proposed by Singer and Nicolson.
(ii) According to this model, there is a central lipid bilayer of phospholipids with their polar head group towards the outside and the non-polar tails pointing inwards.
(iij) Some proteins which are embedded in the lipid layer are called integral or intrinsic proteins and they cannot be separated from the membrane.
(iv) There are large globular integral proteins which project beyond the lipid layer on both the sides are believed to have channels through which water-soluble materials can pass across.
(v) Superficially attached proteins are called extrinsic. or peripheral proteins and can be easily removed.
(vi) Some membrane lipids and integral proteins remains bound to oligosaccharides which project into the extracellular fluid and influence the manner in which cells interact with one another.
Fig. Fluid mosaic model of membrane
