Osmosis: Difference between revisions
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Osmosis is the movement of [[Water|water]] molecules from a high water concentration (hypotonic solution) to a low water [[Concentration|concentration]] (hypertonic solution) through a [[Semi-permeable membrane|semi-permeable membrane.]] It can also be described as the movement of water from a low [[Solute|solute]] concentration to a high solute concentration through a [[Semi-permeable membrane|semi-permeable membrane]]. | Osmosis is the movement of [[Water|water]] molecules from a high water concentration (hypotonic solution) to a low water [[Concentration|concentration]] (hypertonic solution) through a [[Semi-permeable membrane|semi-permeable membrane.]] It can also be described as the movement of water from a low [[Solute|solute]] concentration to a high solute concentration through a [[Semi-permeable membrane|semi-permeable membrane]]. | ||
*Concentration gradients affects osmosis, the higher the concentration gradient the higher the osmosis rate. | *Concentration gradients affects osmosis, the higher the concentration gradient the higher the osmosis rate. | ||
*Osmosis can be decreased by increasing the osmotic pressure of the hypertonic solution relative to the hypotonic solution <ref>Patlak, J., (2000) Osmosis, available at http://physioweb.uvm.edu/bodyfluids/osmosis.htm (last accessed 14/11/2011).</ref>. | *Osmosis can be decreased by increasing the osmotic pressure of the hypertonic solution relative to the hypotonic solution <ref>Patlak, J., (2000) Osmosis, available at http://physioweb.uvm.edu/bodyfluids/osmosis.htm (last accessed 14/11/2011).</ref>. | ||
Osmosis is very important in the biological systems, as water moves across cell membrane by osmosis. Water movement is essential to maintain the osmolarity of the cell. | Osmosis is very important in the biological systems, as water moves across cell membrane by osmosis. Water movement is essential to maintain the osmolarity of the cell. An example of osmosis:<br>Plants absorb water through their roots by osmosis | ||
Cells have a potential problem when maintain their intracellular osmolarity due to metabolites e.g. sugars, amino-acids and nucleotides. These are large in size and highly charged, which attract many counterions. Thus significantly contribute to osmolarity. To control this problem cells actively pump out Na+, so their intracellular fluid contains a decreased number of inorganic ions than the extracellular fluid. This maintains osomotic equilibrium .<ref>(Alberts B et al.,2008:664)</ref> | |||
'''References:''' | <br>. <br> | ||
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Revision as of 17:47, 1 December 2011
Osmosis is the movement of water molecules from a high water concentration (hypotonic solution) to a low water concentration (hypertonic solution) through a semi-permeable membrane. It can also be described as the movement of water from a low solute concentration to a high solute concentration through a semi-permeable membrane.
- Concentration gradients affects osmosis, the higher the concentration gradient the higher the osmosis rate.
- Osmosis can be decreased by increasing the osmotic pressure of the hypertonic solution relative to the hypotonic solution [1].
Osmosis is very important in the biological systems, as water moves across cell membrane by osmosis. Water movement is essential to maintain the osmolarity of the cell. An example of osmosis:
Plants absorb water through their roots by osmosis
Cells have a potential problem when maintain their intracellular osmolarity due to metabolites e.g. sugars, amino-acids and nucleotides. These are large in size and highly charged, which attract many counterions. Thus significantly contribute to osmolarity. To control this problem cells actively pump out Na+, so their intracellular fluid contains a decreased number of inorganic ions than the extracellular fluid. This maintains osomotic equilibrium .[2]
.
References:
- ↑ Patlak, J., (2000) Osmosis, available at http://physioweb.uvm.edu/bodyfluids/osmosis.htm (last accessed 14/11/2011).
- ↑ (Alberts B et al.,2008:664)