Transcript Diffusion & Osmosis

Diffusion &
Osmosis
Ch 8
Diffusion

Definition: Net movement of particles from an
area of _______
high concentration to an area of
______
low concentration

The smell of popcorn traveling
Example: _____________________________
across the room

Diffusion results from the
_________
random movements of
particles (Brownian
motion)

Diffusion is a ________
SLOW
process

3 factors affect the ________
(how
rate
quickly or slowly) of diffusion



Temperature
Temp.
________________
If you increase ________
it will move more
then ______________________
Conc.
Concentration If you increase ________
________________
then __________________________
it will diffuse more rapidly
Pressure
Pressure
________________
If you increase ________
then _______________________
it will increase diffusion

Eventually… the particles will become
evenly distributed
_______

The condition in which there is
continuous movement, but no overall
concentration change is called
dynamic equilibrium
__________________

The difference in concentration of a
substance across a space is called
_______________________
concentration gradient
High
concentration
Low
concentration

In the case with diffusion, particles
high
are moving from an area of _____
low
concentration to an area of _____
concentration; therefore, the
substance is said to move ______
with
the concentration gradient.
 Another
example of diffusion:
Oxygen in the air sacs of lungs 
diffuses into capillaries
 Particles constantly move & bounce
off each other and other surfaces

Osmosis

Definition: Diffusion of water across a
Semi-permeable membrane
_________________

diffusion
Osmosis is a special example of __________
Osmosis

Example: Absorption of water by plant roots
Osmosis

It is important to notice that
large impermeable molecules do not
__________________
H 20
cross the membrane, but _______
molecules
do cross during osmosis

Osmosis occurs in both plant and animal
cells and there are three conditions that
typically appear.

Isotonic Solution


Hypotonic solution


Concentration of dissolved substances in the
same as the concentration of
solution is the _______
dissolved substances inside the cell.
Concentration of dissolved substances is
less in the solution outside the cell than the
_______
concentration inside the cell
Hypertonic solution

Concentration of dissolved substances is
greater outside than the concentration inside
________
the cell
ISOTONIC SOLUTION
10% salt
HYPOTONIC SOLUTION
cell
10% salt
2% salt
cell
HYPERTONIC SOLUTION
10% salt
25% salt
cell
10% salt
Normal Cells in
Isotonic Solution
Cells in Hypertonic
Solution
Cells in Hypotonic
Solution
ISOTONIC SOLUTION
10% salt
HYPOTONIC SOLUTION
cell
10% salt
2% salt
cell
Equal
movement in
and out
HYPERTONIC SOLUTION
10% salt
25% salt
cell
More H2O in
than out
10% salt
More H2O
out than in
Here is what happens when more
water exits or more water enters