Biology coursework-osmosis?

Question

im doin an osmosis investigation. potato cores in a glucose solution and i need to include back ground information about osmsis in my conclusion! anybody know what i can write! need help:)xx

Answer 1

Osmosis is the net movement of a solvent across a semipermeable membrane from a region of high solvent potential to an area of low solvent potential.

The osmotic pressure is defined to be the pressure (force per unit area) required to maintain an equilibrium, with no net movement of solvent.

Osmosis is important in biological systems as many biological membranes are semipermeable. In general, these membranes are impermeable to organic solutes with large molecules, such as polysaccharides, while permeable to water and small, uncharged solutes. Permeability may depend on solubility properties, charge, or chemistry as well as solute size.
Osmosis provides the primary means by which water is transported into and out of cells. The turgor pressure(pressure of the cell contents against the cell wall, in plant cells, determined by the water content of the vacuole, resulting from osmotic pressure ) of a cell is largely maintained by osmosis, across the cell membrane, between the cell interior and its relatively hypotonic environment.

Examples of osmosis

When a plant cell is placed in a hypertonic solution, the water in the cells moves to an area higher in solute concentration, and the cell shrinks and so becomes flaccid [pron. flassid]. (This means the cell has become plasmolysed - the cell membrane has completely left the cell wall due to lack of water pressure on it [the opposite of turgid].

Osmosis can also be seen very effectively when potato slices are added to a high concentration of salt solution. The water from inside the potato moves to the salt solution, causing the potato to shrink and to lose its 'turgor pressure'. The more concentrated the salt solution, the bigger the difference in size and weight of the potato slice.

If we put an animal or a plant cell in a solution of sugar or salt in water
1. If the medium surrounding the cell has a higher water concentration than the cell, the cell will gain water through osmosis. Such a solution is called a hypotonic solution.
2. If the medium has exactly the same water concentration , there will be no net movement of water across the cell membrane. Such a solution is called a isotonic solution.
3. If the medium has a lower concentration of water than the cell, meaning that it is a very concentrated solution the cell will lose water by osmosis. Such a solution is called a hypertonic solution.

Answer 2

av put in mine that its is when water moves from an area of high concentration 2 low conc n all that and give an example of it and reffer back 2 your results 2 gt full marks xx

Answer 3

Try these sites. They ought to give you some good ideas.