Osmosis Flashcards
definition
The movement of water molecules through a partially permeable membrane from a region of higher water potential to a region of lower water potential
What type of process?
Requires no energy - passive process
High water potential
If there are lots of water molecules preset, there is high pressure and therefore high water potential
Low water potential
If there are fewer water molecules present, there is less pressure and therefore low water potential
What is water potential measured in?
In units of pressure - kPa
What has the highest water potential?
Pure distilled water = 0kPa
What affects the rate of osmosis?
Water potential gradient
Thickness of the exchange surface
Surface areas of the exchange surface
How does the water potential gradient affect osmosis?
The higher the water potential gradient, the faster the rate of osmosis. As osmosis takes place the difference in water potential on either side of the membrane decreases so the rate of osmosis levels off over time
How does the thickness of the exchange surface affect osmosis?
The thinner the exchange surface the faster the rate of osmosis
How does the surface area of the exchange surface affect osmosis
The larger the surface area the faster the rate of osmosis
Hypotonic solution
A solution with a lower concentration of solutes
Hypertonic solution
A solution with a higher concentration of solutes
