SiLENT DO NOW
Read the lab when you are done

Explain how the solute will move according to diffusion.
Describe what the cells will look like after diffusion.
(Red = solute
White = solvent)
CELL
‘B’
CELL
‘A’

Agenda







Catalyst (7 minutes)
Diffusion Blitz Review (5 minutes)
OSMOSIS! (7 minutes)
Guided Practice (25 minutes)
Independent Practice (21 minutes)
Egg Lab (25 minutes)
EQ (10 minutes)
HOMEWORK: COMPLETE WORKSHEET
Diffusion
Key Point #1: Diffusion is the net movement
of molecules from an area of high
concentration to an area of low
concentration
 Key Point #2: Diffusion continues until there
is equilibrium
 Key Point #3: Cell membranes are
selectively permeable

Infrared Fart
ON YOUR OWN, IN YOUR NOTES…
 Using the process of diffusion, explain to your
friend why you can smell their fart even though they
are sitting on the other side of the room.
OBJECTIVES
By the end of the period, all SWBAT…
Predict the movement of water using
osmosis

Osmosis!

Key Point #1: Osmosis is the
diffusion of water
Special
kind of diffusion
The solvent (water) moves, instead of
the solute (stuff)

But… why?!?!
Blue=water, Green=solute
Blue=water, Green=solute
So What?

Key Point #2: When cells are
placed in hypertonic or
hypotonic solutions, they change
in volume
Hyper-
= high
Hypo- = low
Iso- = same
Hypertonic
Solution
Inside
Cell
Outside
Cell
70%
water
50%
water
Hypertonic
Solution
Water
Inside
Cell
70%
water
Outside
Cell
Water
50%
water
Water
Hypertonic
Solution
Water
Inside
Cell
60%
water
Water
Outside
Cell
Water
60%
water
Hypotonic
Solution
Inside
Cell
Outside
Cell
22%
water
40%
water
Hypotonic
Solution
Water
Inside
Cell
22%
water
Outside
Cell
Water
40%
water
Water
Hypotonic
Solution
Water
Inside
Cell
30%
water
Water
Outside
Cell
Water
30%
water
Isotonic
Solution
Inside
Cell
90%
water
90%
water
Outside
Cell
Red blood cells in action

http://www.coolschool.ca/lor/BI12/unit4/U04L06/
rbc.html
Whiteboards!
Goal: 60s
Pull into groups
and get your
whiteboards,
please!
Inside
Cell
16%
water
7%
water
Outside
Cell
88%
water
Inside
Cell
54%
water
Outside
Cell
Inside
Cell
1%
water
1%
water
Outside
Cell
Hypo, hyper or isotonic?
40% water inside the cell and 10%
water outside the cell. The cell
membrane is permeable to water.
1)Is this hypertonic, hypotonic, or isotonic?
2)How will the water move, according to
osmosis?
3)What will happen to the cell?
Hypo, hyper or isotonic?
10% water inside the cell and 90%
water outside the cell. The cell
membrane is permeable to water.
1)Is this hypertonic, hypotonic, or isotonic?
2)How will the water move, according to
osmosis?
3)What will happen to the cell?
Hypo, hyper or isotonic?
55% water inside the cell and 55%
water outside the cell. The cell
membrane is permeable to water.
1)Is this hypertonic, hypotonic, or isotonic?
2)How will the water move, according to
osmosis?
3)What will happen to the cell?
PAY ATTENTION!!!

20% SUGAR inside the cell and 22% SUGAR
outside the cell. The cell membrane is
permeable to water.
Hypo, hyper or isotonic?
20% sugar inside the cell and 22%
sugar outside the cell. The cell
membrane is permeable to water.
1)Is this hypertonic, hypotonic, or isotonic?
2)How will the water move, according to
osmosis?
3)What will happen to the cell?
Hypo, hyper or isotonic?
80% sugar inside the cell and 80%
sugar outside the cell. The cell
membrane is permeable to water.
1)Is this hypertonic, hypotonic, or isotonic?
2)How will the water move, according to
osmosis?
3)What will happen to the cell?
Hypo, hyper or isotonic?
9% sugar inside the cell and 1%
sugar outside the cell. The cell
membrane is permeable to water.
1)Is this hypertonic, hypotonic, or isotonic?
2)How will the water move, according to
osmosis?
3)What will happen to the cell?
We’re getting tricky!

Ocean water has a higher concentration of salt than
do human body cells. Imagine that poor Darius is
stranded out at sea, and very thirsty. He drinks a
bunch of seawater.
 What
type of solution is ocean water (hypertonic,
hypotonic, isotonic)?
 What will happen to his cells as a result?
We’re getting tricky!

Ocean water has a lower concentration of water
than do human body cells.
 What
type of solution is ocean water (hypertonic,
hypotonic, isotonic)?
 What would happen to your cells if you drank this
ocean water?
We’re getting tricky!

Distilled water has a higher concentration of water
than do human body cells.
 What
type of solution is distilled water (hypertonic,
hypotonic, isotonic)?
 What would happen to your cells if you drank distilled
water?
We’re getting tricky!

Distilled water has a lower concentration of minerals
than do human body cells.
 What
type of solution is distilled water (hypertonic,
hypotonic, isotonic)?
 What would happen to your cells if you took a bath in
distilled water?
Worksheet
Everyone
loves…
WORKSHEETS!!!

Egg Lab – Day 1


An egg can be thought of as a big cell. After the
shell is removed (with vinegar), it is a partially
permeable membrane.
Putting this egg in a hyper/hypotonic solution will
cause osmosis to occur!
Egg Lab – Day 1
QUESTION: Will an unshelled egg increase or
decrease in mass after being placed overnight in
corn syrup or water?
Egg Lab – Day 1
HYPOTHESIS: Formulate two hypotheses, one for
putting an egg in water, the other for putting an
egg in corn syrup. (Formulate means “create.”)
Example:
CHOOSE ONE
1. If the egg is placed in water, then it will increase/decrease in mass
because ____________.
2. If the egg is placed in corn syrup, then it will increase/decrease in mass
because ____________.
Egg Lab – Day 1
VARIABLES:
 Identify your INDEPENDENT and DEPENDENT
variables.
 Remember:
 Identify
Categories!!!
at least 2 CONSTANTS.
REMEMBER: Variables are categories, not specific
things!
Egg Lab – Day 1
SET UP:
1.
Observe each egg. Record your observations in Data
Table 2.
2.
Calculate the mass of each egg. Record this mass in Data
Table 1.
3.
Label one beaker A and one beaker B. Put one egg in
each.
4.
Add enough acetic acid to the beaker so that you are
completely covering the egg.
5.
In Data Table 2, record detailed observations of the eggs.
How do you use a triple-beam balance?



Calibrate using knob on the left! Make sure balance
is pointing at 0 before you start.
Put object on metal balance.
Start with the highest beam (100 g) increments.
Move it over one by one notch until the balance
goes below 0. Do this for each beam until you have
you balance at 0.
What if we want to take the mass of
an egg?

It might roll off and die!

Correct method:
 Take
mass of the beaker. (WRITE IT DOWN – Data
Table 1)
 Take the mass of the beaker and the egg inside it.
 Subtract the first mass from the 2nd to get the mass of
the egg.
 Mass
of Beaker+Egg – Mass of Beaker = Mass of Egg
Exit Question



Identify the type of
solution
Describe what will
move, and where
Explain how the
cell’s volume will
change
1.
2.
3.
A cell contains a solution that is
44% water, and it is sitting in
a solution that is 70% water.
A cell contains a solution that is
64% water, and it is sitting in
a solution that is 64% water.
A cell contains a solution that is
9% sugar, and it is sitting in a
solution that is 88% sugar.