The Selective Permeability

To understand the selective permeability and work, you must have an idea of ​​what a cell membrane. All living cells are usually encapsulated, or wrapped in a phospholipid bilayer that separates the cytoplasm of the cell’s external environment and facilitates the transport of molecules within and outside the cell. Usually surrounded by a layer of plasma that plays an active role in the control of cellular transport.

As an airport or city, every living cell a check post as a mechanism in its outer membrane, which controls entry and exit of molecules.  As cell biology, known as “selective permeability” of the membrane.  The aim of this article is to explain how the cellular mechanisms that allow cell permeability.

To understand the selective permeability and work, you must have an idea of ​​what a cell membrane.  All living cells are usually encapsulated, or wrapped in a phospholipid bilayer that separates the cytoplasm of the cell’s external environment and facilitates the transport of molecules within and outside the cell.  Usually surrounded by a layer of plasma that plays an active role in the control of cellular transport. 

The selective permeability: Definition

Selective permeability of cell membrane is the site that lets you control entry and exit of molecules in the cell.  This feature allows the cell to separate the cytoplasm from the external environment.  Only molecules that are necessary to maintain the internal processes in the cell that breathes, is allowed to go in, while waste products are allowed to leave.  The importance of selective permeability is simply the ability of the cell to determine what is happening or what is left out!

How selectivity or permeability of the cell makes the differential?  It is possible thanks to a very efficient selection mechanism, consisting of channel proteins in the cell membrane and its porous nature.  Let me briefly explain how the selective permeability of cell membranes work to control the entry and exit of molecules, in the next section.

How selectively permeable?

The chances of any molecule to reach a cell and it is through the membrane depends on its size, structure and concentration outside the cell.  The size is the most important factor to decide, what determines the input mode of the molecule in a cell, followed by concentration and structure.  There are three main ways in which molecules are transported into a cell, including “active transport”, “passive transport” and the transport of vesicles.  “Let me briefly explain each of these mechanisms.

Passive transport
This type of transport is passive, it does not require active participation of the cell membrane by pulling on the molecule.  In this type of transportation, moving a molecule only to the cell through the process of diffusion and osmosis.  This latter mechanism of osmosis is responsible for the transport of water molecules in the cells.  The oxygen is released into the bloodstream through the process of diffusion through cell membranes.  This works for small molecules that can diffuse through the pores in the membrane.  The main point to remember here is that the cell does not use energy to bring these molecules inside.

Active Transport
Molecules that are relatively large, making the process of passive transport does not work.  These molecules, which are necessary for the internal workings of a cell, is transported through the pumping of special mechanisms, which are mediated by the outer shell of plasma (covering membrane lipids).  This type of transport, use of cellular energy and is mainly a function of the plasma membrane.

Transport vesicle
For several molecules, active transport is not useful.  These large molecules are transported into the cell by vesicles, which are small pieces of membrane, such as travel pods, which eject large molecules (exocytosis) or trigger inside (endocytosis).

The study of biology at the cellular level is really amazing.  Incredibly effective mechanisms exist in plant and animal cells make life possible.  In conclusion, the selective permeability of cell membrane property that gives you control over what molecules are ingested or come out of your body.  Is the mechanism that allows cells to maintain their internal equilibrium with the environment.  We hope this article has stimulated his curiosity to delve into this subject more!

0
Liked it
No Responses to “The Selective Permeability”
Post Comment
comments powered by Disqus