MD-10TH AUG http://thegrabup.com/?p=811 Significance Of Osmosis
(700-1200)
Osmosis is a process of movement of solvent through a semi permeable membrane from an area of high water concentration to an area of low water concentration to equalize the concentration of solute to both side of the membrane. . Water is sometimes called "the perfect solvent," and living tissue (for example, a human being's cell walls) is the best example of a semipermeable membrane. Osmosis process as demonstrated below shows that when a beaker is separated into two chambers/compartments by a selectively permeable membrane and both compartments are filled with solvent of different sugar concentration to the same level.
We observe that level of liquid rises on the side containing higher solute (sugar) because the solvent flows from high water concentration zone to low water concentration. This is how osmosis occurs.
Transfer of solvent can be stopped by applying pressure on the side having higher concentration. We can see in the diagram below that when we apply pressure on high solute concentration side, we reach a stage when there is no net flow of water across the membrane and this pressure is called Osmotic pressure. This is called a state of equilibrium. Now when we apply pressure greater than osmotic pressure, we find that flow of water is reversed that is water flows from higher concentration solution to lower concentration solution.
The term osmosis sounds very technical at first encounter and may seem to have no practical use in day to day living but the process of osmosis has been used in various fields such as medicine, water management, medical field, human body. Even it helps plants in receiving water. Food manufacturers use the concept of osmosis for preserving many foods; even in our house our mother uses it for preserving fruits and vegetables.
The principle behind longer shelf life of preserved food involves OSMOSIS....
The need to store food