Biology Coursework
Aim:
Investigating osmosis inside a potato with different concentrations solutions.
A little about Osmosis:
Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low concentration.
Semi-permeable membranes are very thin layers of material (cell membranes are semi-permeable), which allow some things to pass through them but prevent other things from passing through.
Cell membranes will allow small molecules like oxygen, water, and carbon dioxide to pass through. Cell membranes will not allow larger molecules like Sucrose to pass through
If the medium surrounding the cell has a higher water concentration than the cell, the cell will gain water by osmosis. Water molecules are free to pass across the cell membrane in both directions, but more water will enter than leave the cell. The overall result is that water enters the cell and the cell swells up.
If the medium has a lower concentration of water than the cell, the cell will lose water by osmosis. Again water crosses the cell membrane in both directions, but this time more water leaves the cell than enters it. Therefore the cell will shrink.
Prediction:
I predict that in the water, which contains no sucrose, the potato will take in more water particles meaning the potato will weigh more than when it started. The different solution we add, which will contain more sucrose each time will make the potato lighter due to the fact that water particles are being released into the solution from the potato. This is because there are more sucrose particles in the solution than in the potato, meaning osmosis is trying to level out the water particles in both the solution and the potato.
Aim:
Investigating osmosis inside a potato with different concentrations solutions.
A little about Osmosis:
Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low concentration.
Semi-permeable membranes are very thin layers of material (cell membranes are semi-permeable), which allow some things to pass through them but prevent other things from passing through.
Cell membranes will allow small molecules like oxygen, water, and carbon dioxide to pass through. Cell membranes will not allow larger molecules like Sucrose to pass through
If the medium surrounding the cell has a higher water concentration than the cell, the cell will gain water by osmosis. Water molecules are free to pass across the cell membrane in both directions, but more water will enter than leave the cell. The overall result is that water enters the cell and the cell swells up.
If the medium has a lower concentration of water than the cell, the cell will lose water by osmosis. Again water crosses the cell membrane in both directions, but this time more water leaves the cell than enters it. Therefore the cell will shrink.
Prediction:
I predict that in the water, which contains no sucrose, the potato will take in more water particles meaning the potato will weigh more than when it started. The different solution we add, which will contain more sucrose each time will make the potato lighter due to the fact that water particles are being released into the solution from the potato. This is because there are more sucrose particles in the solution than in the potato, meaning osmosis is trying to level out the water particles in both the solution and the potato.
