Diffusion through a Membrane Simulation
Beaker
Cell
Starch
Starch
Molecules
Starch
Glucose
Glucose
Molecules
Starch
Glucose
Iodine
Iodine
Molecules
Give it some
time…….
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Times
Up!
Starch
Glucose
Iodine
Starch
Glucose
Iodine
What Diffused in and out the Cell?
Starch
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Diffused IN
Glucose
Iodine
Water
Starch
Glucose
Iodine
Starch
Diffused OUT
Glucose
Iodine
Starch
Glucose
Iodine
Starch
Didn’t Diffuse at All
Glucose
Iodine
Starch
Glucose
Iodine
What about a real Cell?
Lets look at the
epidermis of a Red
Onion….Up Close.
If we make a wet mount
slide of a Red Onion
Epidermis it would look
like this:
If salt water is added,
there will be more salt
outside the cell than in.
The cell loses water through
osmosis as it tries to create a
ratio of water:salt inside the
cell that matches the outside
This Process is Called
Plasmolysis
What if we add water
without salt?
NYSED Part D
Lab Review
NYSED
Part D
Lab Review
Diffusion and Osmosis
• Designed to help you understand the
concepts of Diffusion and Osmosis and
how these cell processes effect the
cell;
• Define: diffusion, osmosis, hypertonic,
isotonic, hypotonic, saline, selectively
permeable, molecule size;
Part 1: Diffusion
• Diffusion: movement of molecules from an area of
high concentration to an area of low concentration
along the concentration gradient.
• Example is when you put your Lugol’s solution into the
water and the water began to turn the “rust/tea” color.
Before diffusion occurs…
After diffusion occurs…
Part 2: Create a “cell”
•
•
•
•
•
Soak 10 inches of dialysis tubing;
Tie knot in one end;
Put 10mL of glucose solution in and 20mL of starch solution in;
Pinch/clamp closed and put into cellular environment (Lugol’s and
water) for 15 minutes;
Observe the changes and infer what happened
Insert into
“cellular
environment”
Wait
about 15
minutes
and
observe.
After 15 minutes, observe…
• What happened to the glucose in the
“cell”? …the starch in the “cell”? …the
Lugol’s iodine outside the “cell”? Why?
S
G G
GS
I
I
I
G
I
I
At the beginning…
S
G I
IS
G
I
After 15 minutes…
Iodine solution (I)
Glucose solution (G)
Starch solution (S)
And now, the part that makes you cry (ok, not
really, but the “Red Onion” part of the lab)…
• Prepare a wet mount slide of
the inner epidermis of a red
onion section;
• Observe the red onion and
draw what you see;
• Add a couple of drops of
saline (salt) solution to the
epidermis. Wait 5 minutes;
• Observe under microscope
again, note any changes;
• Add freshwater to the slide,
wait 5 minutes, observe
changes again.
Red Onion Plasmolysis Observation
• Before and after observations of red onion
epidermis under the microscope (400X)
Red onion under in isotonic (normal)
solution. Note cell membrane and
cytoplasm almost completely “fill” the
boundary of the cell wall.
Red onion under in hypertonic (salt)
solution. Note cell membrane has
“withdrawn” and the cytoplasm has lost
water to the salty environment, making it
appear smaller and darker.
1. What does the tubing
represent?
Cell membrane
2. What is inside the tubing?
Starch & glucose
3. What did we add to
make the liquid outside
the “cell” amber colored?
Starch indicator (iodine)
4. Why does the inside of
the “cell” turn purple or
black?
High s.i.conc.
Low s.i. conc.
Starch indicator diffused into
the tubing
5. How do we know that
starch did not move from
the inside to the outside?
No color change outside
6. How can we find out if
glucose moved into the
beaker?
?
Glucose
(high
conc.)
Do a glucose indicator test
using the fluid in the
beaker
7. After placing 10 drops
of the amber solution into
a test tube, what do we
add to it?
Glucose indicator
8. After adding the glucose
indicator solution (blue)
what do we do with the test
tube?
Heat it
9. If there is glucose in the
solution, what will happen to
the blue color after heating
the tube for 2 minutes?
The color changes
10. The blue color changed
to orange. This means that
what substance is in the
test tube?
glucose
starch
glucose
C6H12O6
11. Glucose indicator solution was added to these test tubes,
and then the tubes were heated. Which will change color?
Were you right?
“Making
Connections”
NYSED Lab
The new NYSED monument, possibly?
(LE teacher humor, you wouldn’t
understand…)
How many times in one
minute can you squeeze a
clothespin??
• An interesting take on the
entire lactic acid build-up
argument.
First, Look for a pattern…
Taking your pulse is rather simple. Use the index and middle finger
of one hand to palpate (feel) the arterial pulse in your radial artery
on your wrist.
Count for 15 seconds and multiply by 4 to determine the number of
times your heart beats in one minute.
Pulse Rate
Trial #1 ____X 4 = _____ bpm
Trial #1 ____X 4 = _____ bpm
Trial #1 ____X 4 = _____ bpm
Note: The NYSED “Making
Connections” Lab measures for 20
seconds and multiplies by 3, but
any calculation that leads to a
count of 60 seconds is acceptable.
Collect “Class Data” and prepare a “histogram”
of your results…
Pulse Rate per
minute (range
of averages)
<51
51-60
61-70
71-80
81-90
>90
Number of
students in this
range
And now, develop and draw your histogram…
<51
51-60
61-70
71-80
Average Pulse Rate Range
81-90
>90
And now, make a hypothesis…
Student A
Student B
If you exercise first, then you
should be able to squeeze a
clothespin more times in one
minute.
If you rest first, then you
should be able to squeeze a
clothespin more times in one
minute.
Explain why…
Explain why…
Now, do your “experiment” and
collect your data…
3... 2… 1… GO!!! Start
counting the number of
Squeezes for one FULL
minute and record your data.
The Beaks of
Finches
NYSED Lab
What is the “goal” of the lab?
• Demonstrate how Darwin’s
Finches (those that he
observed on the Galapagos
Islands) have adapted new
beaks yet remain similar to the
shared common ancestor that
most likely came from the
mainland.
Required Supplies for “B of F”
A randomly
assigned “beak”
Small seed island
Petri dish
Large seed island
Timer
Round 1
• Only one seed at a time may be eaten. To
be “eaten” it must land inside your
stomach.
• If you scoop seeds or eat more than one
at a time, you “choke” and vomit all of your
seeds out.
• Average is taken from four trials, 60
seconds each.
And now, Round 1…
Seeds Collected
Partner #1
Trial #1
Partner #1
Trial #2
Partner #2
Trial #3
Partner #2
Trial #4
Average
Did you average over 13 seeds?
YES
Go to Round 2
Increased
Competition
NO
Repeat Round 1
on the “big seed”
island with the
same beak
Successful in Round 1?
Welcome to Round 2!!!
Repeat the same procedure but this time
have another “bird” to compete against!
Round 2 - Increased Competition
Seeds Collected
Partner #1
Trial #1
Partner #1
Trial #2
Partner #2
Trial #3
Partner #2
Trial #4
Average
Compete the table and move on to Round
3 where there is “Increased Competition” if
you average over 13 seeds.
Unsuccessful in Round 1?
Go to a “large seed” island and start over (even though you have starved to death, you are resurrected)
Seeds Collected
Partner #1
Trial #1
Partner #1
Trial #2
Partner #2
Trial #3
Partner #2
Trial #4
Average
Did you average over 13 seeds this time?
YES
Go to Round 2, but
with another large
seed eater as
competition on the
“large seed” island
NO
Get a new “beak”
and try yet again
(not a possibility
in nature)
Successful in Round 2?
Welcome to Round 3!!
Increased Competition
(more than 1 other bird)
Repeat the same procedure but
this time have even more birds to
compete against!
Seeds
Collected
Partner #1
Trial #1
Partner #1
Trial #2
Partner #2
Trial #3
Partner #2
Trial #4
Average
Don’t fret. It is almost over!
Not successful in Round 2?
“Here endeth the lesson…”
So, what did you learn?
• Birds have evolved many different mechanisms and
modifications that make them more well-adapted to
the environment in which they live.
• Structural differences (in beaks) are significant
enough to make you into a new species, but you did
descend from a common ancestor.
• The adaptations that are contribute to the most
success allow that individual to survive and
reproduce.
• The adaptations that are contribute to a lack of
success are not passed on since they either starve
or have no “breeding rights”.
Relationships
and
Biodiversity
NYSED Lab
Review
Please note:
• “Curol” is a fictitious plant extract mentioned in
the NYSED lab that has the ability to effectively
treat cancer. IT DOES NOT EXIST. Likewise,
any “Curol” images included in this presentation
are simply images taken from an internet search
and are not a cancer cure. It is simply a product
found with a similar name. I do not know what it
is used for as the website was not translated into
the English language.
What does this lab entail?
• Seven tests that look at the physical,
chemical, and microscopic characteristics
of three plants that may be able to create
Curol, even though they are not Botana
curus (the plants that does produce it).
• Comparison of data to determine
relationships.
• Define the crucial need for biodiversity.
Test 1 - Structural Characteristics
of Plants
QUESTION:
Botana curus
Which leaves most
closely resemble the
leaves produced by
Botana curus?
Species Z
Record your
observations in the data
table.
Species Y
Species X
Test 2 – Structural Characteristics
of Seeds
QUESTION:
Botana curus seeds
Which seeds most
closely resemble the
seeds produced by
Botana curus?
Species X seeds
Record your
observations in the
data table.
Species Z seeds
Species Y seeds
Test 3 – Microscopic Internal
Structures of Stems
QUESTION:
Botana curus
Which stem
structures most
closely resemble
the stem
structures of
Botana curus?
Species X
Record your
observations in
the data table.
Species Y
Species Z
Test 4 – Paper Chromatography to
Separate Plant Pigments
Water migrates
up paper via
capillary action
and carries
plant pigments
with it.
B.curus
X
Y
Z
“Spot” your
chromatography paper
and label it with a pencil.
B.curus
X
Y
Z
Test 5 – Indicator Tests for Enzyme M
Botana curus
Botana curus
(“fizzed” a little)
Species X
Species X
(no “fizz”)
Species Y
Indicator
Enzyme
M
Species Y
(“fizzed” a little)
Species Z
Species Z
(“fizzed” a little)
Put two drops of each plant
Extract in separate wells of
the well tray.
Add a small
sprinkle of
“Indicator
Enzyme M”
Record your results.
Test 6 – Using Simulated Gel
Electrophoresis to Compare DNA
The strips below represent the DNA strands extracted from each plant (B.
curus, X, Y, and Z). Each strand will be “cut” between a double C/double G.
Therefore, lines are drawn below where each strip should be cut. Then,
count up the number of bases and paste appropriately in the simulated Gel
Electrophoresis table on the next slide.
Botana curus
AT T C C G GAT C GAT C G C C G G ATATA C T C C G G TAATAT C
Species X
AT T G TAC C G G G AT C C G G AC G T C G C GA C TAATATAG C A
Species Y
AC C G G T C C G G G AT C G CAC C C G G TA C T C C T G TAATAT C
Species Z
AT T C C G GAT C GAT C G C C G G ATAT T C T C C G G TAATAT
Simulated Gel Electrophoresis
# of
Bases
Botana curus
Species X
Species Y
Species Z
24
-
23
GGACGTCGCGACTAATATAGCA
22
21
20
19
18
GGTACTCCTGTAATATC
17
16
15
14
13
12
GGATCGATCGCC
GGGATCGCACCC
GGATCGATCGCC
11
GGATATACTCC
GGATATACTCC
GGTAATATC
GGTAATATC
10
9
8
ATTGTACC
7
GGGATCC
6
5
ATTCC
GGTCC
ATTCC
4
3
2
1
ACC
+
Test 7 – Molecular Evidence for
Relationships
Botana curus
CAC
GTG
GAC
TGA
GGA
CTC
CTC
mRNA
GUG
CAC
CUG
ACU
CCU
GAG
GAG
Amino acid
Val
His
Leu
Thr
Pro
Glu
Glu
Species X
CAC
GTG
GAC
AGA
GGA
CAC
CTC
mRNA
GUG
CAC
CUG
UCU
CCU
GUG
GAG
Amino acid
Val
His
Leu
Ser
Pro
Val
Glu
Species Y
CAC
GTG
GAC
AGA
GGA
CAC
CTC
mRNA
GUG
CAC
CUG
UCU
CCU
GUG
GAG
Amino acid
Val
His
Leu
Ser
Pro
Val
Glu
Species Z
CAC
GTA
GAC
TGA
GGA
CTT
CTC
mRNA
GUG
CAC
CUG
ACU
CCU
GAA
GAG
Val
His
Leu
Thr
Pro
Glu
Glu
Amino acid
And where did you get those Amino
Acids from???
Your friend and mine… The Universal Genetic Code Chart
So, what is the closest and most probable
alternative source for Curol???
Test
Most similar to Botana curus?
Test 1 – Structural Characteristics of Plants
Species Z as it has the same kind of parallel
veination in the leaves.
Test 2 - Structural Characteristics of Seeds
Species Z seeds are flat and striped, much the
same as Botana curus seeds are.
Test 3 – Microscopic Internal Structure of Stems
Species Z vascular bundles closely resemble
those of Botana curus.
Test 4 – Paper Chromatography of Pigments
Species Z and Botana curus share a similar
pattern of pigmentation in paper chromatography.
Test 5 – Indicator Tests for Enzyme M
While many “fizzed”, once again Species Z and
Botana curus reacted the same.
Test 6 – Simulated Gel Electrophoresis
Identical banding pattern in both Botana curus
and Species Z.
Test 7 – Amino Acid Comparison
Species Z and Botana curus have the most
similarities.
And the winner is…..
(insert drum roll here…)
Species Z