Diffusion

1
Diffusion Movement of materials from an area of
high concentration to an area of low
concentration.
H
L
Concentration is the amount of something in a
defined area.
When there is no longer a difference in high to
low, when particles are evenly spread out in an
area
equilibrium
2
Osmosis
A type of diffusion
The diffusion of water from a high concentration
to a low concentration through a selectively
permeable membrane.
If the cell has a 25 salt content, what is the
of water?
75 water
H
If the environment of the cell is 80 salt, what
is the of water?
L
20 water
Hypertonic soln
The High water is where?
Inside
The cell shrinks
The Low water is where?
Outside
3
Osmosis
A type of diffusion
The diffusion of water from a high concentration
to a low concentration through a selectively
permeable membrane.
If the cell has a 75 salt content, what is the
of water?
H
25 water
L
If the environment of the cell is 20 salt, what
is the of water?
80 water
Hypotonic soln
The High water is where?
Outside
The cell swells
Inside
The Low water is where?
4
Osmosis
A type of diffusion
The diffusion of water from a high concentration
to a low concentration through a selectively
permeable membrane.
If the cell has a 20 salt content, what is the
of water?
80 water
If the environment of the cell is 20 salt, what
is the of water?
80 water
Isotonic soln
Is there High water?
No
The cell is in equilibrium
No
Is there Low water?
5
Osmosis
If an animal cell gets into an environment where
osmosis into the cell is too great, it will burst.
One celled critters have a built in sump pump
called a contractile vacuole which pumps out
excess water and maintains a water balance.
No
Why?
Can a plant cell burst?
It has a strong cell wall
Turgor Pressure
The amount of pressure when the cell membrane
pushes against the cell wall