Download DIFFUSION

Cell Processes 1
windows
 GET OUT
HOMEWORK
 Do Now: How can you
 Homework: Activity
sheet (TBD…)
Door
smell perfume that
someone sprays from
across the room????
Brainstorm!!
DEMO!
Terms Review
 Selectively Permeable – will only allow certain things to pass
through it
 Permeable – means things can pass
 Selective – not everything
 The cell membrane is selectively permeable to molecules
 “Semi-permeable”
 Sometimes the membrane will allow “other” molecules to
pass, other times it will only allow water molecules to pass.
Terms Review
 Solvent vs. Solute
 Kool-Aid
 Solvent =
 Solute =
Water
Sugar
 Iced Tea
 Solvent = Water
 Solute =
Tea
Solute and Solvent??
 Hypertonic – high concentration of solute
 When you’re hyper, you have more energy!!
 Hypotonic – low concentration of solute
 Isotonic – same concentration of solutes (when comparing
two solutions)
 Hypertonic solution means more solute in the solution than
in the cell
DIFFUSION: Movement of molecules of
any substance from a high concentration
to a low concentration.
WHAT DOES THAT MEAN?
This can happen in the open air, or through a selectively
permeable membrane!!
How?
 Molecules are always moving and bumping into each other
 More molecules = more collisions
 Collisions push the molecules away from each other slowly
•Molecules like their own space.
•If there are too many in one space then molecules
will move to a place with less stuff (less
molecules).
DOES NOT
NEED
ENERGY TO
MOVE!
HIGH
CONCENTRATION
HOW DIFFUSION WORKS
Molecules move in and out of the cell
through the cell membrane
Draw arrows to show which way the molecules will move
Where do you observe this?
 Helium balloons
 Perfume/cologne
 Cigarette smoke
 Cooking pasta
OSMOSIS
The movement of water through a
membrane
DOES NOT
NEED ENERGY
TO MOVE!
How do you dilute something??
 There is way too much
sugar powder in your drink
after you make Kool-Aid.
 1. Try to remove the solute
(difficult)
 2. Add more solvent!
 How do you fix this?
(water)
What are the consequences to
a cell if too much water goes…?
 INTO THE CELL
 OUT OF THE CELL
SHRINKS
BLOATS
Isotonic
Hypotonic
Hypertonic
ACTIVE TRANSPORT
NEEDS ENERGY to “move”
substances across the
membrane
•USUALLY MOVES SUBSTANCES FROM A LOW CONCENTRATION
TO A HIGH CONCENTRATION
How?
 Transport proteins – Think back to chemicals of life
 “Proteins make up some cell parts”
 Transport proteins allow active transport to happen!
Active Transport
 Brain Pop Video
 https://www.brainpop.com/science/cellularlifeandgenetics
/activetransport/
PASSIVE TRANSPORT
DON’T NEED ENERGY to
“move” substances across
the membrane
•USUALLY MOVES SUBSTANCES FROM A HIGH CONCENTRATION
TO A LOW CONCENTRATION
Question:

Which of the following statements concerning
diffusion and active transport is correct?
A. Both diffusion and active transport
require cell energy.
B. Neither diffusion nor active transport
require cell energy.
C. Diffusion requires cell energy while
active transport does not.
D. Active transport requires cell energy
while diffusion does not.