History Of Cell Membrane :: essays research papers

In the early stages of the twentieth deoxycytidine monophosphate, little was known about cubicle membranes. Until the early 1950s, the biological cell membrane was rarely mentioned in scientific literature. It was recognised that roughthing was probably there, only hardly anything about it was known. Considering the lack of technical equipment available a century ago, scientists such as Charles Overton and Edwin Gorter were not only exploring new territory in looking at the properties of cell membranes, but laying the way for incoming cell biologists. Scientists had to wait another fifty years for the discovery of the electron microscope, let alone seventy years for the advent of freeze fracturing techniques.Nageli and Cramer in 1855 had already suggested that biological cells are separated from their environment by a membrane possessing special characteristics, and in 1900 Overton performed some simple but classical music experiments which proposed that cell membranes were co mposed of lipids (1). By measuring the permeability of various compounds across the membrane of a frog muscle, Overton found some interesting results. He observed that lipophilic molecules (molecules attracted to fat solvents) could easily cross this cell membrane, until now larger lipid insoluble molecules could not. He also observed that itty-bitty polar molecules could slowly cross the membrane. Other experiments with the likes of hen eggs suggested the strawman of a lipid layer in the membrane. These results became known to biologists across the human being and it was generally accepted that a semi-permeable lipid membrane surrounded some if not all cells (2).Although this was opening new doors for cell biologists, the information was wide disregarded. One hundred years ago biological fact was establish on what could be seen and since the proposed lipid membrane was smaller than the wavelength of visible wakeful it could not be studied under the light microscope. Most biol ogists exclusively concerned themselves with more evident structures. However, some scientists continued to dedicate their beat to examining this &8216invisible&8217 structure.Two such biologists were the Dutch Edwin Gorter and F. Grendel. They recognised in 1925 that twain such lipid layers existed.