Membrane Receptors

Membrane receptor is a protein molecule that are specific to the cell membrane, (hormones, neurotransmitters, drugs) external molecules them, causing a change in cell function, was added. This process is called transduction: external signal, is introduced into the action. Also known hundreds of receptor, no doubt, more and more, are just some yet to be discovered. Many drugs exert their therapeutic effect by blocking or activating a membrane receptor.

The membrane receptor, direct evidence for them suggest that it was in existence long before it was not. As of 1889 at the earliest, the first evidence came from the work of physiologist Langley nerve synapses in the UK. (Axon unit of the central nervous system, and postganglionic fibers, sympathetic with the synapse between nerve cells that do not dominate the heart organ, eye, and intestinal) paint drug solution of nicotine to the ganglion. This means that the nerve ganglion ganglion before, it is enabled, then inhibition of control organ, Langley noted that nicotine cause agitated by postganglionic nerve. Similarly, when the nicotine nerve agent and is located on the intersection of the skeletal muscle fibers, suggesting that to mimic the chemical signals emitted from motor nerve, muscle fibers, flinch.

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Vagus nerve is stimulated, the heart slows down, Dixon, proposed in 1907 that have been released from the nerve endings to something be reconciled with the “body” of the heart muscle. We had to wait a Nobel Prize for the discovery of pharmacologist Ottorebi, of Germany reported in 1921 demonstration of chemical transmission. If You idea of ​​experiments had in a dream, he has created a frog heart perfusion of two perfusate like came first, from second Ottorebi. Beating vagus nerve, heart slow when stimulated it, after a few seconds, the first is connected to the heart and the second layer. To emancipate the mind first, some substances caused (Lowy “is Vagusstoff” is called), the equivalent flow of second, and nerve stimulation. Accordingly opinion (this experiment does not prove that the material came from the vagus nerve trunk itself) to receive the chemical signal that there is a host site was born.

Cells is different from the outside, intracellular membranes are determined areas or limited space usually it is possible to maintain the environmental chemical or biochemical. For an example of a cell membrane of the peroxisome shield around the remainder from dividing cells and peroxide of cell membrane around it. Organelle Most are referred to as organelle “coupling film”, is defined by these films.Perhaps the most important function of biological membranes are selectively permeable structure. This means that the chemical properties of the other size of the molecules or atoms are trying intersection to determine whether they can do so, and cost. Selective permeability is essential for effective separation of cell organelles or cells from the environment. Further biological membranes and has elastic properties, or some mechanical. Particles are not able necessary for cell function, but spread freely on the membrane is obtained by endocytosis or enter the membrane transport protein.

The filopodia membrane of postsynaptic their hair whip, the tip of the cilium, and side bottom presynaptic, microvilli, and lamellipodia: can be many types of separating cells from the external environment in the plasma membrane of specialized , as well as the muscle cell membrane of the muscle cells, neurons and myelin membrane professional dendritic spines. Further cell membrane, it is possible to form a mobile node structure “supramembrane” different such caveolae, synaptic density, Podosomu, invadopodium, desmosomes, hemidesmosomes, and focal adhesion. The membrane of these types of protein and lipid composition is different. And (outer membrane and the inner membrane) er surface roughness, sarcoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria (inner membrane and the outer membrane) core, peroxisome, vacuole, cytoplasmic granules in endosomes: Smooth and type of the film also The granules and melanosomes (synaptosomes, acrosome, of hromafinna secretory vesicles to create a cell organelles, and (COPII coated vesicle phagosome, autophagosome, clathrin-coated vesicles, and were COPI coated) vesicles of the cell including).

I have a protein composition and lipid type of biological membranes are different. The content of the membrane determines the biological properties and their physical. As a matter discharge pump pumping the drug of such cells, some components of the film, plays an important role in health care. Plasma membrane that surrounds the cytoplasm of living cells or cell membrane, to separate the intracellular components of the extracellular medium physically. It has a cell wall that prevents the passage of large molecules fungi, also plants and bacteria, and more, to provide mechanical support to the cage. Further cell membrane, cytoskeleton plays a role in strengthening can to assist cell group and forms a fabric, providing a form of placing cells and the other cells in the extracellular matrix.

Membrane is a selectively permeable, it is possible to facilitate the transport of materials needed for survival, to adjust what and out of the cell. The movement of substances across the membrane, the active cell or generated, without the introduction of “passive” cellular energy may be either a request to spend energy on its transport. Further, the film is, I maintain the cell potential. In this way, the cell membrane acts as a selective filter that you can either enter certain things, goes out of the cell. Cell uses a number of transport mechanisms, including biological membranes.