The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment. While Robert Hooke's discovery of cells in 1665 led to the proposal of the cell theory, Hooke misled the cell membrane theory that all cells contained a hard cell wall since only plant cells could be observed at the time. The lipid bilayer hypothesis, proposed in 1925 by Gorter and Grendel, created speculation in the description of the cell membrane bilayer structure based on crystallographic studies and soap bubble observations. In an attempt to accept or reject the hypothesis, researchers measured membrane thickness. These researchers extracted the lipid from human red blood cells and measured the amount of surface area the lipid would cover when spread over the surface of the water. Since mature mammalian red blood cells lack both nuclei and cytoplasmic organelles, the plasma membrane is the only lipid-containing structure in the cell. Consequently, all of the lipids extracted from the cells can be assumed to have resided in the cells' plasma membranes. The ratio of the surface area of water covered by the extracted lipid to the surface area calculated for the red blood cells from which the lipid was 2:1(approx) and they concluded that the plasma membrane contains a lipid bilayer. Evolutionary, cell membranes are an amazing conquer and invention, because it could concentrate the chemical solutes inside, enhancing the probability of stochastic encounters among them and the diversity of chemical reactions. This is a side view of a computer-generated membrane.

#molecularart ... #membrane ... #lipids ... #cell

Structure rendered with @proteinimaging and depicted with @corelphotopaint