What is Plasmalemma?

Plasmalemma is another name of the plasma cell membrane. In general, each cell has one of these membranes that acts as a wall containing the content to separate from the surrounding environment. Plasmalemma is constructed from lipids, more often known as fats and proteins. Some of the proteins are fixed and some may move in the cell membrane. Many proteins are involved in the transport of molecules to and out of the cell, while others help maintain cellular structure, act as receptors or participate in chemical reactions as enzymes. Most lipids are present in the form of phospholipids that have a phosphate head and the tail of fatty acids. The phosphate heads are soluble in water while tails are not. Phospholipids are arranged in the membrane, so the heads soluble in the water point to the watery extracellular enomes of the cells form Vihorn and water cytoplasm. The ends of the tail that are not soluble in water are oriented together in the middle of the membrane.

approximately half of the plasmalemma consists of protein. These proteins have two types: integral proteins inside the double layer of lipids and peripheral proteins loosely bound to the membrane surface. Of the integral proteins, some, called transmembrane proteins, they pass directly through the lipid double -layer and protrude on each side, while others are contained just inside the inner or outer part of the membrane and protrude only from one of its surfaces.

A number of membrane proteins are involved in moving substances in and outside cells. For example, in the structure of bacterial cells, they pump membrane proteins in ammonia from which nitrogen nitrogen can be extracted. Some proteins in the plasmalmm are molecules of adhesion of cells which combine cells to each other and to the basement membranes, while others participate in chemical reactions and are known as enzymes, or act as receptors for substances such as hormones. When hormones bind to such receptors, it causesThis changes in the cell. In muscle or nerve cells, membrane proteins are involved in creating and sending electrical pulses.

Although plasmalemma fluid and proteins may move in it, some of which are limited to certain areas where specific functions allow. In epithelial cells lining the intestines, some proteins are concentrated in the apical membrane, the upper surface of the cell that projected into the opening of the intestine. Others are limited to the basolateral membrane on the sides and the lower surfaces of the cell. This ensures that the absorption of nutrients from the intestine occurs on one cell surface before the substances pass through the cell and are transported to the blood vessels on the other side of the cell.