Transcript Chapter+4+Diffusion+and+Osmosis+Teacher`s+Copy+(Slides)

How were you able to smell
the perfume?
Movement of Substances
Diffusion
Osmosis
Diffusion
Lets Recap…
3 particle states of matter
What is the particle
arrangement and motion?
Solid
Diffusion
Liquid
Gas
Diffusion
Definition:
1)The net movement of particles
2)from a region of higher concentration
3)to a region of lower concentration
High concentration
Low concentration
Diffusion in liquid state
: Ink dye
: Water
molecules
Diffusion in liquid state
: Ink dye
: Water
molecules
Diffusion in gaseous state
: Perfume
molecules
: Air
molecules
Diffusion in gaseous state
: Perfume
molecules
: Air
molecules
Net Movement
Note: This barrier
does not illustrate a
partially permeable
membrane.
Net Movement
Equilibrium
When particles reaches an equilibrium, does the particles
stop moving?
Hint: Particles move in a random and dynamic motion.
Examples
Movement of
substances in and
out of amoeba cells
Movement of CO2
and O2 in and out of
lung cells
Movement of
nitrates in and
out of root hair
cells
Can you think of any other
diffusion that happens in
your daily life?
Concentrated
sucrose solution
1. What will happen to the eggs?
2. Is this diffusion? If not what is
this process called?
Movement of Substances
includes
Diffusion
definition
Net movement of particles
from a region of high
concentration to a region
of low concentration,
down the concentration
gradient.
Key Ideas:
1) Liquid/ Gas particles move
from region of high concentration
to low concentration
2) Movement of particles is
random and dynamic in
equilibrium (net)
3) Examples of diffusion
Osmosis
Osmosis
Osmosis
Definition:
The movement of water molecules
through a partially permeable membrane
from a solution of high water potential,
to a solution of lower water potential.
Partially permeable
membrane
: sucrose
:water
molecules
Partially
Permeable Membrane
•Allows some substances to pass
through but not others.
Permeable
Membrane
•Allows both the solvent
(water) and the solutes (
dissolved substances to
pass through)
•Eg: Cell membrane in plant and animal
cells.
•Eg: Cell Wall of plant cells
The movement of water molecules through a
partially permeable membrane
•Only water molecules passes through the partially permeable
membrane (sucrose solution too big to pass through the partially
permeable membrane).
Partially permeable
membrane
: sucrose
:water
molecules
Osmosis in living organisms
Plant Cells
Animal
Cells
Plant cell behaves differently from animal cell
when placed in solutions with differing water
potentials.
•Due to presence of cell wall in plants.
Osmosis in plant cell
Fully permeable: allows most
dissolved substances to pass
through
Cell surface membrane is a
partially permeable membrane
Plant cell in
High water potential
1. Cell vacuole has lower
water potential compared to
solutions outside cell
2. Water enters cell by
osmosis.
3. Vacuole increases in size,
pushes against cell wall
4. Cell wall exerts opposing
pressure
5. Plant cell expands
Osmosis in living organisms
Plant Cells
Animal
Cells
Plant cell behaves differently from animal cell
when placed in solutions with differing water
potentials.
•Due to presence of cell wall in plants.
Animal cell in
High water potential
1. Cytoplasm has lower
water potential
compared to solution
outside cell
2. Water enters by
osmosis
3. Animal cell will swell
and may bursts as
it does not have a
cell wall to protect it.
Movement of Substances
includes
Diffusion
definition
Net movement of particles
from a region of high
concentration to a region
of low concentration,
down the concentration
gradient.
Key Ideas:
Osmosis
Active
Transport
definition
The movement of water
molecules through a
partially permeable
membrane from a
solution of high water
potential, to a solution of
lower water potential.
Opposites!
Key Ideas:
1) Liquid/ Gas particles move
1) Only water molecules
from region of high concentration
to low concentration
2) Movement of particles is
random and dynamic in
equilibrium (net)
2) Partially permeable membrane
3) High water potential to low
water potential
3) Examples of diffusion
4) Osmosis in living cells
Movement of Substances
includes
Diffusion
definition
Net movement of particles
from a region of high
concentration to a region
of low concentration,
down the concentration
gradient.
Key Ideas:
1) Liquid/ Gas particles move
from region of high concentration
to low concentration
2) Movement of particles is
random and dynamic in
equilibrium (net)
3) Examples of diffusion
Osmosis
definition
The movement of water
molecules through a
partially permeable
membrane from a
solution of high water
potential, to a solution of
lower water potential.
Key Ideas:
1) Only water molecules
Active
Transport
definition
Energy is used to move
particles against
concentration gradient (
from a region of low
concentration to a
region of higher
concentration) , up a
concentration gradient.
Key Ideas:
2) Partially permeable membrane 1) Requires energy
2) From low to high
3) High water potential to low
3) Only in living cell
water potential
4) Active transport in
living cells
4) Osmosis in living cells