Osmosis: Passage of a solvent (such as water) from a lower-concentration solution to a higher-concentration solution, through a semi-permeable membrane (that allows the solvent to pass but not what is dissolved in it) separating the two solutions. The flow of solvent stops when both solutions become equal in concentration. In nature, osmosis. Osmosis definition: Osmosis is gradual absorption. (noun) An example of osmosis is slowly learning how to sew after sitting next to an experience seamstress.

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osmosis

[oz-mo´sis, os-mo´sis] the diffusion of pure solvent across a membrane in response to a concentration gradient, usually from a solution of lesser to one of greater solute concentration. adj., adj osmot´ic.
The process of osmosis and the factors that influence it are important clinically in the maintenance of adequate body fluids and in the proper balance between volumes of extracellular and intracellular fluids.
The term osmotic pressure refers to the amount of pressure necessary to stop the flow of water across the membrane. The hydrostatic pressure of the water exerts an opposite effect; that is, it exerts pressure in favor of the flow of water across the membrane. The osmotic pressure of the particles in a solute depends on the relative concentrations of the solutions on either side of the membrane, and on the area of the membrane. The osmotic pressure exerted by the nondiffusible particles in a solution is determined by the numbers of particles in a unit of fluid and not by the mass of the particles.

os·mo·sis

(os-mō'sis),

osmosis

(ŏz-mō′sĭs, ŏs-)n.pl.osmo·ses(-sēz)1.

os·mo·sis

(oz-mō'sis)

osmosis

(oz-mō′sĭs) [Gr. osmos, impulse, + osis, condition]

reverse osmosis

osmotic (oz-mot′ik), adjectiveillustration

osmosis

The automatic movement of the fluid part of a solution through a membrane, separating two quantities of the solution, in such a direction as to dilute the solution of higher concentration. The membrane is permeable to the liquid but not to the dissolved substance. Such a membrane is said to be semipermeable and membranes of this kind occur widely in the body. Osmosis is an important principle on which much of physiology is based.

osmosis

the movement of a solvent (water in biological systems) through a differentially permeable membrane from a solution with high water concentration and low solute concentration, to one with a low water concentration and high solute concentration.

osmosis

os·mo·sis

(os-mō'sis)
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Osmosis is the net movement of solvent molecules through a semipermeable membrane. It is similar to as the movement is downhill, meaning from higher to lower concentration. In osmosis though, the movement has to occur across a semipermeable membrane. Without this element, it cannot be called osmosis.While diffusion is often depicted as the net movement of solutes between two solutions, osmosis is about the net movement of the solvent molecules, such as water molecules. The differing concentration of water molecules between the two sides of the membrane is what drives the water to move so as to equalize the concentrations of the two areas.

Osmosis definitionIn biology, osmosis is defined as the net movement of molecules through a semipermeable membrane (e.g. ) from an area of higher to an area of lower. Other definitions of osmosis are as follows:.

The process of a diffusing through a semipermeable membrane from an area of low solute concentration to an area of high solute concentration. The tendency of to flow from a (low concentration of dissolved substances) to (higher concentration of dissolved substances) across aIn chemistry, osmosis is defined similarly.

It is the passage of a pure solvent from a solution of lesser to one of greater concentration of solutes when the two solutions are separated by a membrane that selectively prevents the passage of solute molecules while allows the solvent molecules to pass through. A schematic diagram showing how osmosis worksFor osmosis to occur these elements should be present: (1) net downhill movement of water molecules, (2) a selectively-permeable membrane, and (3) osmotic gradient. Water molecules tend to move, and they move downhill, i.e. From an area of high water concentration (or fewer solutes) to an area of low water concentration (or greater solutes). If there is no net movement of water, it cannot be called osmosis.

It should also incorporate a semipermeable membrane to move across. Without it, the process is only a case of and not osmosis. Since water molecules are polar molecules, they need channel proteins to move down their. These channel proteins are embedded on the cell membrane and provide a hydrophilic passageway through which water can move across. What drives the water molecules to move is the osmotic (pressure) gradient, i.e.

Differences in osmotic pressures between the two solutions. Choice of the dragon. The measure of the relative tendency of water to move from one area to another is referred to as.

It is commonly represented by the Greek letter Ψ (Psi). Solutions that have different tonicities will cause a net flow of water across the cell membrane. In this diagram, the is shown how osmosis and the tonicity of solutions affected the cell. The cell in hypotonic solution resulted in the efflux of water leaving the cell to shrink.

In isotonic solution, the cell apparently remains the same since the amount of water molecules leaving the cell is about the same as the amount of water entering the cell. In hypotonic solution, the cell swelled from the influx of water.A is comprised essentially by (substance to be dissolved) and (the component that dissolves the solutes). The concentrations of the constituents of the two solutions shall determine if a solution is, or as compared to another solution. IsotonicAn is a solution wherein the amount of solutes is basically the same as the number of solutes of another solution. For instance, a cell that is isotonic to the outside solution means that both the cell’s intracellular fluid and the surrounding fluid will have equal osmotic pressure and the same water potential. In this case, there will be no net movement of water molecules between the cell and the outside fluid. HypotonicA is a solution that has lower osmotic pressure (or has less solutes) than another solution to which it is compared.

In this case, water moves toward the area with less water concentration or towards the more concentrated region so as to dilute the solution. For instance, when the fluid surrounding the cell is hypotonic, the water will move across the membrane towards the more concentrated solution, which is inside the cell. HypertonicA is a solution that is apparently opposite of the hypotonic solution. A hypertonic solution will have more solutes and less water than the other solution. If a cell is immersed in a hypertonic solution water will leave the cell to dilute the solution outside.

Examples of osmosis Osmosis in animal cellsIn biological systems, osmosis is essential since many biological membranes are, and it leads to different effects. For example, when animal cells are exposed to a surrounding (or lower water concentration) the water will leave the s causing the cells to shrink. This condition is referred to as crenation. Conversely, when the animal cells are placed in a surrounding (or higher water concentration), the molecules will move into the s causing them to swell. If osmosis continues and becomes excessive the cells will eventually burst. Osmosis in plant cellsThe cell bursting due to too much water influx does not happen in plant cells. Plants are able to counter the excessive osmosis through their cell walls and vacuoles.

The cell wall exerts osmotic pressure that stabilizes the plant cell. In fact, is what makes to stay upright. The large vacuole inside the plant cell also helps through, a regulatory process where water potential is regulated so that the osmotic pressure inside the cell is kept within the optimal range.The plant cells, though, are not protected by water efflux. When a plant cell is placed in a surrounding, the cannot prevent the cell from losing. This lead to cell shrinking or the cell becoming.

See also.References. Biology-Online Editors. (2014, May 12).

Diffusion and osmosis. Retrieved from Biology-Online Dictionary Biology-Online Dictionary website:. Biology-Online Editors.

(2014, May 12). Turgor pressure and osmosis. Retrieved from Biology-Online Dictionary Biology-Online Dictionary website:. Biology-Online Editors. (2014, May 12). Concentration gradient and osmosis.

Retrieved from Biology-Online Dictionary Biology-Online Dictionary website:. Biology-Online Editors. (2014, May 12).

Passive transport. Retrieved from Biology-Online Dictionary Biology-Online Dictionary website:© Biology Online. Content provided and moderated by Biology Online Editors.