What are phospholipids?
phospholipids are just one type of large group of organic compounds called lipids. The main role of phospholipids in living organisms is that they form a cell membrane. Lipids form a large and diverse group of compounds that contain carbon (C), oxygen (O) and hydrogen (H) and are insoluble in water, or do not dissolve in water. All lipids fall into one of two groups - fat or oil. The only difference between these groups is that the fats are solid at the room temperature, while the oils are liquid.
The chemical structure of lipids varies between many different types. Most of them are triglycerides, or consist of three chains of fatty acids connected to glycerol molecule. All lipids contain the same glyceolic molecule, so it is the nature of fatty acids that determines the characteristics of lipid. All fatty acids consist of a carboxyl group (-COOH) connected to a hydrocarbon chain, which consists of atoms of carbon and hydrogen. Hydrocarbon chains with moThe thickets are in length and are hydrophobic or repelling water.
phospholipids are not triglycerides. Compared to triglycerides, there is a small but very important difference in phospholipid structure. Instead of having three fatty acids connected to the glycerol molecule, one is replaced by a phosphate group composed of phosphorus, oxygen and hydrogen. The phosphate group is hydrophilic or attracted to water, unlike the rest of the molecule. The fact that one part of the molecule attracts water, while the rest affects the role of phospholipids in the cell membrane.
In water -based solution, phospholipids are automatically arranged in a double layer or phospholipid double -layer. Fatty acids that repel water are found in the middle of a double -layer. Hydrophilic heads that contain the phosphate group point outwards along the two -layer and line of both sides. Because of this creation, some substances will be able to pass DThe vojvrestvo and others will not work as a natural boundary.
The function of the cell membrane is to act as a boundary between the interior of the cell and its surrounding environment. It consists of almost exclusively phospholipid double -layer and proteins. Molecules that are soluble in water or dissolve in water cannot pass phospholipid biloer due to the hydrophobic interior. The role of some proteins found in the double -layer is to be transported across it, both to and from the cell. In this way, phospholipids and proteins control what enters and leaves the cell.