Investigation to find the effect of concentration
on the effect of osmosis
Aim:
To find the effect of concentration on osmosis
Preliminary Work:
Osmosis is a specific type of diffusion. It occurs when a membrane has tiny holes in it that let water molecules pass through, but stops larger molecules like sugar. A membrane that allows only the small molecules through is called a semi permeable membrane. Therefor an impermeable membrane allows no molecules through and a permeable membrane allows all molecules through.
Osmosis is where water molecules diffuse or move from an area of high water concentration to an area of low water concentration. Put simply osmosis is the diffusion of water.
Diagram 1:
An example of osmosis showing the movement of water molecules
between adjacent cells:
This diagram above shows how when the concentration of water molecules is higher than in the cell next to it they diffuse through the cell membrane.
Osmosis occurs in plant and animal cells. The cell membrane of the cells is semi permeable. So if a cell containing a strong concentration of water is next to a cell with a low concentration of water, water molecules pass from the high concentration to the low concentration. In a plant cell water moves from cell to cell by osmosis. This evens out the water in a plant and helps transport water around the cells. The maximum amount of water able to be taken in by a plant cell is controlled by the cell wall, which stops the expansion of the cell and so stops it from bursting.
In an animal cell the level of water in the body is controlled by osmoregulation. This occurs in the kidneys. The kidneys control the level of water in the blood stream keeping it at a constant level. If you drink an excess amount of water then special sense organs detect this and your kidneys respond by increasing the amount of water in the urine. As a result, a greater amount of more dilute urine is excreted until the water level in the tissue is back to normal again. The opposite occurs when too little water is present in the blood supply, water loss is kept to a minimum so the amount of urine excreted is decreased but of a higher concentration. This is necessary as if the concentration was too high then the cells would lose water and become dehydrated, if the concentration becomes too dilute then the cells will take in excess water and burst.
on the effect of osmosis
Aim:
To find the effect of concentration on osmosis
Preliminary Work:
Osmosis is a specific type of diffusion. It occurs when a membrane has tiny holes in it that let water molecules pass through, but stops larger molecules like sugar. A membrane that allows only the small molecules through is called a semi permeable membrane. Therefor an impermeable membrane allows no molecules through and a permeable membrane allows all molecules through.
Osmosis is where water molecules diffuse or move from an area of high water concentration to an area of low water concentration. Put simply osmosis is the diffusion of water.
Diagram 1:
An example of osmosis showing the movement of water molecules
between adjacent cells:
This diagram above shows how when the concentration of water molecules is higher than in the cell next to it they diffuse through the cell membrane.
Osmosis occurs in plant and animal cells. The cell membrane of the cells is semi permeable. So if a cell containing a strong concentration of water is next to a cell with a low concentration of water, water molecules pass from the high concentration to the low concentration. In a plant cell water moves from cell to cell by osmosis. This evens out the water in a plant and helps transport water around the cells. The maximum amount of water able to be taken in by a plant cell is controlled by the cell wall, which stops the expansion of the cell and so stops it from bursting.
In an animal cell the level of water in the body is controlled by osmoregulation. This occurs in the kidneys. The kidneys control the level of water in the blood stream keeping it at a constant level. If you drink an excess amount of water then special sense organs detect this and your kidneys respond by increasing the amount of water in the urine. As a result, a greater amount of more dilute urine is excreted until the water level in the tissue is back to normal again. The opposite occurs when too little water is present in the blood supply, water loss is kept to a minimum so the amount of urine excreted is decreased but of a higher concentration. This is necessary as if the concentration was too high then the cells would lose water and become dehydrated, if the concentration becomes too dilute then the cells will take in excess water and burst.
