 Happy Tuesday 
Bellwork:
Quickwrite – In 42 words, summarize your HW
using the words concentration, diffusion,
osmosis, equilibrium, isotonic, hypertonic, and
hypotonic.
On Page 17 of your I.A.N. Title “Egg Lab” and
draw the following data table:
Original
Mass
VINEGAR
SYRUP
WATER
XXXXXXXXX
Final Mass
Difference
in Mass
XXXXXXXXX
Appearance
of Egg
On Page 17 of your I.A.N. Title “Egg Lab”
and draw the following data table:
Original
Mass
VINEGAR
XXXXXXXXX
Final Mass
Difference
in Mass
Appearance
of Egg
XXXXXXXXX
SYRUP
WATER
The shell that surrounded your egg was dissolved by
soaking the egg in vinegar for 24 hours. The vinegar
dissolved the hard calcium carbonate shell exposing the
semi-permeable membrane that surrounds the egg.
This membrane is very similar to the plasma membrane
that surrounds all of our cells. The purpose of this lab is
to simulate osmosis across a plasma membrane.
Students will receive one egg per lab table.
Day 1 Procedure…
1. Using your hands, carefully remove your egg from the
vinegar and use a paper towel to pat it dry.
2. On your data table, record the firmness and overall
appearance of your egg in the VINEGAR row.
3. Mass (weigh) your egg on a triple beam balance and
record your results on your data table. Enter the weight
under the “Final Mass” for VINEGAR and the “Original
Mass” for SYRUP.
4. Using a piece of glassware tape and a marker, label the
beaker with your period and table letter. Cover the egg
with syrup until it begins to float.
5. Allow your egg to sit for 24 hours.
Diffusion Notes
Why does food coloring spread out in
water?
Every living thing lives in a liquid
environment that it needs to survive.
One of the most important functions of the cell
membrane is to regulate the movement of
dissolved molecules from the liquid on one side
of the membrane to the liquid on the other
side.
The concentration is
the amount of a
substance dissolved
into water.
Kool-Aid
Beaker 1
Beaker 2
Beaker 3
In a solution,
particles are
constantly
moving.
They collide
with one
another and
tend to spread
out randomly.
Particles move from an area of high
concentration to an area of low
concentration.
This process is known as diffusion.
A concentration gradient is a
difference between two
concentrations.
Diffusion is the movement of
particles down the concentration
gradient.
When the
concentration of a
solute is the same
throughout a
system, the system
has reached
equilibrium.
When equilibrium is
reached, particles
do continue to
move across the
membrane.
Substances that diffuse across a membrane
do not require the cell to use energy.
If a substance is able to
diffuse across a
membrane, the
membrane is said to be
permeable to it.
If a substance cannot
diffuse across a
membrane, the
membrane is said to be
impermeable to it.
Selectively permeable means that some substances
can pass across while others cannot.
Biological membranes are selectively permeable.
Diffusion of water through a selectively
permeable membrane is called osmosis.
When two solutions have the same
concentration of solute they are said to be
isotonic.
Isotonic means “same strength”.
Draw This
A solution that has a higher concentration of
solute is said to be hypertonic.
Hypertonic means “above strength”.
Draw This
A solution that has a lower concentration of
solute is said to be hypotonic.
Hypotonic means “below strength”.
Draw This