State Diffusion Lab
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The page numbers in this presentation
refer to the New York State Diffusion
Through a Membrane Lab Handout
Slide 2
Refer to page 2
The initial set up
The “Cell” filled with
glucose and starch
solutions
Water & Iodine in the
beaker covers the
“cell”
Slide 3
#9 on page 2
Predict what you think will diffuse in this set up.
Remember: There’s starch and glucose inside
the “cell” and iodine outside the cell.
Be sure to write where you believe the
substances will move (into or out of the cell).
Slide 4
Refer to page 3
Chemical Test Results:
Blue-colored Glucose Indicator Solution
Please remember that you must heat
the test tubes containing Benedict’s
Solution for this color change to
occur!
*If it turns orange/red when heated,
glucose is present.
On your data table, write the color of
each solution in the appropriate
space.
Slide 5
Page 3 continued
Chemical Test Results Amber-colored Starch
Indicator Solution:
On your data table, record
the colors in the
appropriate spaces on the
data table.
Refer to page 4
Slide 6
Changes to the original lab set up from slide 2.
On your lab at the 2nd
bullet point, record the
changes you see. Go
to the next slide if you
do not remember how
it looked in the initial
stage.
What has changed?
INITIAL STAGE
Slide 7
FINAL STAGE
There is one visible difference between the two…write about this difference,
at the 2nd bullet point on page 4 of your lab.
Slide 8
Page 4- 3rd bullet point
Results of the glucose test on the water from
the beaker in the final state of the set up in
Part 1 of the lab.
Beaker solution
with Benedict’s
before heating
Beaker
solution with
Benedict’s
after heating
Refer back to slide
4 if you need a
reminder about
what this color
change means
(positive for
glucose or negative
for glucose).
Slide 9
Page 4 Initial and Final State
I
S G
Use the letters I, S, and G to represent the substances used. I’ve done the Initial
State for you. Refer back to the chemical test results (slides 7 & 8) and the set
up images to complete the Final State diagram
Slide 10
Pages 4 & 5
Answer questions #1-6.
Questions #1-3 use the information on pages 3
& 4 of the lab to answer.
Question #6 can be answered using the
information found on the front of the lab.
For question #7 on page 5, you will re-draw
exactly what you did back on page 4.
Slide 11
Part 2- Osmosis
Please read the information on
pages 5 & 6, then continue on
page 7 (next slide)
Page 7 onion cell
Typical red
onion cells
mounted in
water:
Look at the pink part
(the cytoplasm
surrounded by a cell
membrane)
Page 7- onion cell continued
First answer #8 on
page 7. Then draw
an onion cell in salt
water at the
bottom of the page.
Look at the cytoplasm,
now. It is darker and
smaller…the cell wall is the
same size.
Page 8
Answer question
#11.
Examine the image
at right (onion cell in
Fresh water).
Describe the
appearance of the
cells at right for
question #13
Draw a diagram of an onion cell in
Fresh water. It will look like your
original drawing on page 7.
Answer the Analysis Questions
It will help you to draw a diagram for each question. Here’s an example of
what you might draw…
Water will diffuse out
98%
water
95%
water
The End