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biology 0610printed 42 · PDF 42
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Higher the temperature, faster the diffusion. This is because at high temperature the
particles have more kinetic energy so particles will move faster thus higher the rate of
diffusion
Distance
More the distance less the rate of diffusion. The particles will have to travel more
distance which will lead to slower rate of diffusion
Concentration Gradient
The greater the concentration gradient, the greater the diffusion rate. More
concentration gradient means more particles which will lead to particles spreading out
quickly .
Surface area
The greater the surface area of an object the more the rate of diffusion. If the surface
area of a cell is bigger it means more particles can enter it at a time so faster rate of
diffusion.
Osmosis
It is the net movement of water particles from an area of higher water potential to an
area of lower water potential.
Also down the concentration gradient
Water can move in and out of the cell through the process of osmosis.
No energy is required for this process
For osmosis to take place the presence of partially permeable membrane is a must
Osmosis in animals
If there is more concentrated solution in the animal cell(less water potential area) and
the outside of the cell has more diluted solution(more water potential) then the water
particles will travel from outside of the cell(high water potential) to inside of the
cell(low water potential). Sometimes in an animal cell so much water enters the cell
through osmosis that the cell bursts. This happens because an animal cell doesn't
have a cell wall to prevent it from bursting.
Osmosis in plants
In plants osmosis also takes place from an area of higher water potential to an area of
less water potential. In plants if too much water enters the cell through osmosis then
the cell would not burst because the cell wall will stop it from bursting.The cell
becomes turgid. The pressure of the water pushing outwards on the cell wall is known
as turgor pressure. Turgor is important to keep the leaves firm and plant upright. If the