In 1871 Hugo de Vries cell membrane permeability for ammonia and glycerol, this was leading upto the first successful X-ray study by Bernal and Crowfoot in 1934 of the globular protein pepsin, however even though it shows water covering the protein surface, it doesn’t show it in high resolution. Many years has past with more testing and experiments but it wasn’t until 1925 when E, Gorter and F, Grendel proposed the phospholipid layers in the cell membrane which resulted in them doing first bilayer structure experiment test, obtaining this by measuring the size of water surface that phospholipids taken from red blood cell can cover, the area in which it covered was nearly twice as much as the total area of red blood cells used to
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The flaws in Davson and Danilli’s model are that not all membranes the same nor are they symmetrical, they have different actions in chemical composition and structures, membranes have distinctive faces inside and out. The proteins within the membrane are not soluble in water, like the phospholipid layer they and amphipathic, meaning they repel against it. Plus they found that the protein layers are not likely to work, as the hydrophobic areas would be in a watery environment, which would then cause the hydro phospholipids to separate from the water. If the proteins were to be on the outside layer of the membrane this would make it an unstable structure. Their model predominated the era till Singer and Nicolson’s proposed the Fluid Mosaic model, putting an end to all other models of the cell membrane, since Singer and Nicolson’s proposition in 1972 no changes have been made to their Fluid Mosaic model as it wasn’t necessary, using this model they further explained the structure and function of the cell membrane.
Singer and Nicolson used the word mosaic to describe that there were many components to the membrane than Davson and Danilli had first explained, not just phospholipids and proteins, but other molecules such as cholesterol and carbohydrates, although the phospholipids and proteins and the major