In 1871 Hugo de Vries permeability of the cell membrane for ammonia and glycerol, this led to the first successful X-ray study by Bernal and Crowfoot in 1934 on the globular protein pepsin, however also although you show the water covering the protein surface, you don't show it in high resolution. Many years passed with further tests and experiments, but it was not until 1925 when E, Gorter and F, Grendel proposed phospholipid layers in the cell membrane that led them to perform the first experimental test on the bilayer structure, achieving this by measuring the size of surface water that the phospholipids taken from the red blood cells can cover, the area covered was almost double the total area of ​​the red blood cells used to extract the phospholipids, consequently this proved to be a fortunate discovery in the double structure layer and with more accurate measurement and due to the presence of proteins within the membrane the ratio between the two surfaces would not have been 2:1, although this original finding could not be duplicated as stimulated membrane research, l 'has pointed in the right direction. In 1985 M. Diesenhofer, R. Huber and H. Michel showed the structure of the membrane protein in high resolution, showing alpha helical transmembrane segments. In 1935 two men, Hugh Davson and James Danilli proposed a model of the structure of the cell membrane describing it as consisting of two layers, a phospholipid bilayer and a protein layer, the phospholipid layers being sandwiched between the protein layers, the following diagram shows how they proved this theory. James Danilli intended to further explain in the Davson and Danilli model the observations on surface tensions in the lipid bilayer and even if there were some defects… middle of paper… a cytoplasm in the proposed physical confirmation. As if the oil and water were left to sit, after being shaken they will separate, meaning the hydrophilic and hydrophobic elements will arrange themselves in the correct order to isolate them from contact with the polar components. They supported their theories with both physical and biochemical evidence. During the research they had successfully separated bilayers of frozen cell membranes from different areas to show the proteins embedded within, other evidence had also shown to support the existence of transmembrane proteins. Works Cited http://en.wikipedia.org/wiki/Davson– Danielli_model, accessed February 11, 2014. http://www.whatislife.com/education/fact/history.htm, accessed February 10 2014http://home.earthlink.net/~dayvdanls/CampOLs/MemModels.html, accessed February, 10, 2014.