Question

Explain unit membrane hypothesis ?

Answer 1

According to Robertson, the unit membrane consisted of a bimolecular lipid leaflet sandwiched between outer and inner layers of protein organized in the pleated sheet configuration. Such an arrangement was presumed to be basically the same in all cell membranes. In the late 1950s, electron microscopy provided additional information about the structure of the plasma membrane. Robertson and others demonstrated that the tri-laminar pattern was characteristic of many other cellular membranes, including the endoplasmic reticulum. In view of the underlying unity in the appearance of the cell membranes studied, Robertson proposed his now famous unit membrane model. Though Robertson acknowledged specific chemical differences between membranes (i.e., the particular molecular species that make up each membrane differ), he proposed that the pattern of molecular organization was fundamentally the same. Although there can be no doubt about the similar electron-microscopic appearance of nearly all membranes, so strict a chemical interpretation to account for the uniformity is no longer supportable.