Osmosis
Osmosis is the overall movement of water from a DILUTE to a MORE CONCENTRATED solution through a partially permeable membrane.
- A partially permeable membrance is just one that only allows certain substances to diffuse through it.
- A partially permeable membrance is just one that only allows certain substances to diffuse through it.
Osmosis cont. & Active Transport
Animals Must Regulate Their Water Content
1) Animal cells can't withstand big changes in the amount of water they contain.
2) If too much water moves into an animal cell by osmosis, it can rupture (burst), killing the cell.
3) If too much water moves out of an animal cell, it shrivels up and can't function properly.
Some Chemicals can be Moved by Active Transport
Sometimes chemicals, e.g. glucose, need to be moved from an area with a lower concentration of the chemical to an area with a higher concentration (against the concentration gradient). This is done by a process called active transport. Glucose is reabsorbed in the kidneys by active transport.
1) Animal cells can't withstand big changes in the amount of water they contain.
2) If too much water moves into an animal cell by osmosis, it can rupture (burst), killing the cell.
3) If too much water moves out of an animal cell, it shrivels up and can't function properly.
Some Chemicals can be Moved by Active Transport
Sometimes chemicals, e.g. glucose, need to be moved from an area with a lower concentration of the chemical to an area with a higher concentration (against the concentration gradient). This is done by a process called active transport. Glucose is reabsorbed in the kidneys by active transport.
