structure and function of plasma membrane in cells Essay
‘The structure and importance of the plasma membrane found within and around all cells’
The plasma membrane surrounds all eukaryotic and prokaryotic cells. Eukaryotic cells have membrane bounded organelles whereas prokaryotic cells do not. The plasma membrane forms the boundary between the cell cytoplasm and the environment. Its function are to allow different environments to be established inside and outside the cell. It also controls the movement of substances into and out of the cell.
The cell surface membrane which surrounds all cells consists of many components, which together is referred to the fluid mosaic model. It is called fluid because the individual phospholipids can move relative to one another, making the membrane …show more content…
The importance of the plasma membrane in keeping certain substances inside the cell is shown when someone has cholera. The bacteria, vibrio cholerae, starts to produce a toxic protein which has two parts. One of the parts binds to a specific carbohydrate receptor (a glycolipid) on the cell-surface membrane. Only the epithelial cells of the small intestines have the specific receptor which binds to the toxic, hence why it only effects this part of the body. The other toxic part enters the epithelial cells, which causes the ion channel of the cell-surface membrane to open, so the chorine ions which normal are contained within the epithelium cells floods into the lumen of the small intestines. This has serious effects on the body as it results in water loss from the blood and tissues which causes symptoms such as diarrhoea and dehydration.
Intrinsic proteins completely span the phospholipid bilayer from one side