Osmosis Flashcards
osmosis definition
the movement of water molecules across a partially permeable membrane from an area of higher water potential to an area of lower water potential
What is a partially permeable membrane
one with very small holes in it, which lets some molecules through it but not others
Where do water molecules go and why
both ways through the membrane during osmosis
because there are no more water molecules on one side than on the other
osmosis is a type of what
diffusion
The solution surrounding the cell will always have what
different concentration to the fluid inside the cell
meaning water will either move into the cell from the surrounding solution or out of the cell by osmosis
define an isotonic solution
-they have the same water potential as each other
-there is no net flow of water between the two solutions
define a hypotonic solution
-they have a lower solute concentration and so a higher water potential than another solution
-water will move from this to a hypertonic solution
define a hypertonic solution
-has a higher solute concentration and so a lower water potential than another solution.
-water will move from this to a hypotonic
how are lungs and small intestine of mammals adapted to the exchange of materials
Having a large surface area
A membrane that is thin
how are gills in fish adapted to the exchange of materials
-many gill filaments, giving a large surface area
-gills are thin, (short diffusion distance)
-good supply of blood (maintain a concentration gradient)
-water continuously flows
how are plants adapted to the exchange of materials
-broad and flat providing a large surface area
-leaves are thin (short distance for the diffusion of gases)
how are plant root hair cells adapted to the exchange of materials
root hair cells increase the surface area of a root to allow oxygen to diffuse quicker
Osmosis is a passive process, what does this mean
it doesn’t require any energy input
