The document describes experiments measuring diffusion of plant pigments and osmosis in plant cells. Four plant specimens were tested by placing pieces in water, heated water, vegetable oil, or heated oil to observe diffusion of pigments. Results showed lipidsoluble pigments like carotenoids and flavonoids diffused more quickly through oil. A separate experiment on plasmolysis in onion, apple, and spiderwort cells observed changes when placed in hypotonic and hypertonic solutions, showing effects of osmosis. A third experiment determined the sucrose concentration causing plasmolysis in spiderwort cells to estimate their solute concentration.

1. TRANSPORT OF MATERIALS
ACROSS CELL MEMBRANES &
PLANT-CELL WATER RELATIONS
GROUP 2 Alcantara. Catindig. Ignacio. Kim.

2. DIFFUSION OF SELECTED
PLANT PIGMENTS

3. 4 plant specimens

4. Methodology
plant specimen
A B C D
dH2O dH2O veg. oil heated
+ veg. oil
H2O bath
*a total of 16 test tubes were used

5. Methodology
Set aside for 30 minutes
Shake test tubes
Compare color intensities.
Record results.

6. Results
Bixa orellana
Test tube 1 (w/ dH2o) +++
Test tube 2 (w/ heated dH2o) ++++
Test tube 3 (w/ veg. oil) +
Test tube 4 (w/ heated veg. oil) ++

7. Results
Zingiber officinale
Test tube 1 (w/ dH2o) +
Test tube 2 (w/ heated dH2o) ++
Test tube 3 (w/ veg. oil) +++
Test tube 4 (w/ heated veg. oil) ++++

8. Results
Solanum toberosum
Test tube 1 (w/ dH2o) +
Test tube 2 (w/ heated dH2o) ++
Test tube 3 (w/ veg. oil) +++
Test tube 4 (w/ heated veg. oil) +++

9. Results
Allium cepa
Test tube 1 (w/ dH2o) ++
Test tube 2 (w/ heated dH2o) +++
Test tube 3 (w/ veg. oil) +
Test tube 4 (w/ heated veg. oil) +

10. Discussion
 Diffusion: directed movement of molecules
from a region of high concentration to a region
of lower concentration random thermal motion
 Affected by: Concentration and size of
diffusing particles

11. Discussion
 Bixa orellana
 contain the pigments bixin and orelline
 Carotenoid pigments
 Lipid-soluble due to long hydrocarbon chain
 Zingiber officinale
 contain flavonoids
(quercetin, rutin, catechin, epicatechin, kaempfero
l and naringenin)
 Lipid-soluble due to the ring-like carbon
structures.

12. Discussion
 Red Onion
 Anthocyanin: water-soluble
 Quercetin: lipid-soluble
 Potato skin
 Contains carotenoid pigments
(neoxanthin, violaxanthin and lutein)
 Lipid-soluble

13. Discussion
 Bixin and orelline were able to diffuse much
faster than the others
 Carotenoids are able to reach high
concentrations within chromoplastids and may
actually form crystals
 Large amount of bixin and orelline increased
the rate of their diffusion throughout the
medium

14. OSMOSIS
CELL CHANGES IN
PLASMOLYSIS

15. Osmosis: Cell Changes in
Plasmolysis
 OSMOSIS
 Diffusion
of water across a semi-
permeable membrane

16. Osmosis: Cell Changes in
Plasmolysis
• A Tradescantia spathacea leaf was obtained and
strips of its lower epidermis were prepared using a
1 blade.
• A wet mount was made using the lower epidermis
and the cells were observed under the
2 microscope.
• Water was drawn off the slide with tissue paper
and was replaced with a drop of 5% NaCl.
3

17. Osmosis: Cell Changes in
Plasmolysis
• The cells were again observed
under a microscope and
4 changes were noted.
• The procedure was repeated
using white onion and then
5 apple skin.

18. Discussion of Results
Tradescantia spathacea
Wet mount 5% NaCl

19. Discussion of Results
Allium cepa
Wet mount 5% NaCl

20. Discussion of Results
Malus
Wet mount 5% NaCl

21. Discussion of Results
 Turgid cell
 happens when cell is hypotonic to the
surrounding solution
 optimal for plants
 Plasmolyzed cell
 happens when cell is hypertonic to the
surrounding solution; plasma membrane lysis
 may cause cell death
 cell wall still intact

22. Discussion of Results
 Anthocyanin
 water-soluble pigment
 discoloration in plasmolysis

23. Conclusion
 Osmosis is the diffusion of water through a
semi-permeable membrane and this can be
observed using different epidermal cells with
pigments
 Cells in hypotonic solutions become turgid and
cells in hypertonic solutions become
plasmolyzed as water goes in and out of the
cell, respectively.

24. FACTORS AFFECTING
INTEGRITY OF CELL
MEMBRANE

25. Methodology
Red apple
peel
Under the
In test tubes
microscope
A: Distilled + B: Distilled + C: Distilled + D: 50% E: 50% F: 0.1M
G: 0.1M HCl
Room Temp Refrigerator 60° Chloroform Acetone NaOH

26. Results
Test Tube Intensity of Color
A (room temp.) +++
B (refrigerator/cold) ++
C (water bath/ 60 C) +
D (Chloroform) +
E (Acetone) ++
F (NaOH) +++
G (HCl) ++++

27. Discussion
 Red violet pigment in apples: ANTHOCYANIN
 Found at the vacuole
 Too big to exit cell membrane and tonoplast

28. Discussion
 Heat: Denatures proteins; destroys membrane
 Cold: fatty acid tails rigid; less permeability
 Organic Solvents interact with bilayer causing
disruption of membrane
 Low and High pH: destroys tertiary and
quaternary structure of pigments

29. DETERMINATION OF SOLUTE
CONCENTRATION OF CELLS
(PLASMOLYTIC METHOD)

30. Methodology
10
Drops of sucrose solution + Tradescantia spathacea
epidermal strips
(0.1M, 0.2M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M and
1.0M)
30 minutes

31. Methodology
Wet mount
The number of PLASMOLYZED and
UNPLASMOLYZED cells were recorded
as well as the concentration that caused
INCIPIENT PLASMOLYSIS.
The OSMOTIC POTENTIAL value was Observed under the
also calculated. microscope

32. Discussion of Results
 OSMOSIS: diffusion of water across a semi-
permeable membrane
 Water potential (Ψw)
 Important in determining the direction of osmosis
 High to low Ψw

33. Discussion of Results
 PLASMOLYSIS:
 shrinkingof a cell due to water loss
 happens when a cell is submerged in a hypertonic
solution
Source: http://www.excellup.com/interbiology/planttransportquestion.aspx

34. Discussion of Results
 The cell wall is permeable to water and
sucrose.
 The plasma membrane is permeable to water
but not to sucrose.
Sucrose + Water

35. Data showing the osmotic potential, number of plasmolyzed and
unplasmolyzed cells, total number of cells counted, and the percentage of
plasmolyzed cells found under the microscope for each concentration of
sucrose solution used.
Sucrose Osmotic Total # of %
Plasmolyze Unplasmolyz
Concentrati Potential Cells Plasmolyze
d Cells (#) ed Cells (#)
on (M) (bars) Counted d
0.1 -2.5 6 145 151 3.97
0.2 -5.0 20 174 194 10.31
0.3 -7.5 41 84 125 32.8
0.4 -10.0 90 105 195 46.15
0.5 -12.5 99 88 187 52.94
0.6 -15.0 186 85 271 68.63
0.7 -17.5 112 83 195 57.44
0.8 -20.0 76 54 130 58.46
0.9 -22.5 89 61 150 59.33
1.0 -25.0 172 73 245 70.20

36. 

37. Data showing the osmotic potential, number of plasmolyzed and
unplasmolyzed cells, total number of cells counted, and the percentage of
plasmolyzed cells found under the microscope for each concentration of
sucrose solution used.
Sucrose Osmotic Total # of %
Plasmolyze Unplasmolyz
Concentrati Potential Cells Plasmolyze
d Cells (#) ed Cells (#)
on (M) (bars) Counted d
0.1 -2.5 6 145 151 3.97
0.2 -5.0 20 174 194 10.31
0.3 -7.5 41 84 125 32.8
0.4 -10.0 90 105 195 46.15
0.5 -12.5 99 88 187 52.94
0.6 -15.0 186 85 271 68.63
0.7 -17.5 112 83 195 57.44
0.8 -20.0 76 54 130 58.46
0.9 -22.5 89 61 150 59.33
1.0 -25.0 172 73 245 70.20

38. Discussion of Results
 percentage of plasmolyzed cells increased
as the concentration of sucrose in the
solution increased.
 sucrose concentration of 0.6M - 68.63% of
plasmolyzed cells

39. Discussion of Results
 INCIPIENT PLASMOLYSIS
 osmotic potential of the cell is the same as the
solution’s
 the protoplast just fills the cell volume and neither
exerts pressure to the cell wall nor withdraws
from it
 50% of plasmolyzed cells

40. Data showing the osmotic potential, number of plasmolyzed and
unplasmolyzed cells, total number of cells counted, and the percentage of
plasmolyzed cells found under the microscope for each concentration of
sucrose solution used.
Sucrose Osmotic Total # of %
Plasmolyze Unplasmolyz
Concentrati Potential Cells Plasmolyze
d Cells (#) ed Cells (#)
on (M) (bars) Counted d
0.1 -2.5 6 145 151 3.97
0.2 -5.0 20 174 194 10.31
0.3 -7.5 41 84 125 32.8
0.4 -10.0 90 105 195 46.15
0.5 -12.5 99 88 187 52.94
0.6 -15.0 186 85 271 68.63
0.7 -17.5 112 83 195 57.44
0.8 -20.0 76 54 130 58.46
0.9 -22.5 89 61 150 59.33
1.0 -25.0 172 73 245 70.20

41. Discussion of Results
Concentration where incipient plasmolysis
occurred
is 0.5M with a 52.94% of plasmolyzed
cells.

42. Discussion of Results
 The osmotic potential (Ψs), in bars, of the
sucrose solutions were computed using this
formula:
where:
m = concentration of the solute expressed as molality
(moles solute/ kg H2O)
i = ionization constant
R = gas constant (8.314 J/mol∙K)
T = absolute temperature (C + 273)

43. Discussion of Results
 Sample computation:
Osmotic potential of a 0.1 M sucrose solution
Ψs = -(0.1 mol/L)(1)(8.31 J/K-mol)(300K)
Ψs = -249.3 J/L (0.01 bars/ 1 J/L) = -2.493 bars
Ψs ~ -2.5 bars

44. Data showing the osmotic potential, number of plasmolyzed and
unplasmolyzed cells, total number of cells counted, and the percentage of
plasmolyzed cells found under the microscope for each concentration of
sucrose solution used.
Sucrose Osmotic Total # of %
Plasmolyze Unplasmolyz
Concentrati Potential Cells Plasmolyze
d Cells (#) ed Cells (#)
on (M) (bars) Counted d
0.1 -2.5 6 145 151 3.97
0.2 -5.0 20 174 194 10.31
0.3 -7.5 41 84 125 32.8
0.4 -10.0 90 105 195 46.15
0.5 -12.5 99 88 187 52.94
0.6 -15.0 186 85 271 68.63
0.7 -17.5 112 83 195 57.44
0.8 -20.0 76 54 130 58.46
0.9 -22.5 89 61 150 59.33
1.0 -25.0 172 73 245 70.20

45. Conclusion
 As solute concentration increased, osmotic
potential became more negative along with the
water potential
 % of plasmolyzed cells also increased as water
potential became more negative
 Water diffuses to a region with a more negative water
potential
 To equilibrate the concentration of water inside of cell
to that of the surrounding solution, water moved out of

46. ESTIMATION OF THE WATER
POTENTIAL OF STORAGE TISSUE
(VOLUME CHANGE METHOD)

47. Methodology
• Eleven sets of five potato cylinders (each potato
cylinder 1cm long) were cut off from a large potato
1 and immediately placed in 50 mL beakers
• 20-ml of one concentration of sucrose solution
(0.1 M-1.0 M, with 0.1 graduations) were placed in
2 the 10 separate beakers respectively.
• The remaining beaker contained 20 mL distilled
water
3

48. Methodology
• The fresh weights of each set were
recorded. The potato cylinders were
removed after 90 minutes and weighed
4 again.
• The difference between the initial and
final weights were divided by the initial
weight, and then multiplied by 100 to get
5 % weight change.

49. Discussion of Results

 ∆weights of the potato cylinders=caused
by the presence of sucrose (this stimulated
the cells to generate an osmotic potential
(Ψs))

50. Discussion of Results

 Osmotic potential reduces the free
energy of the system.
 The effect of osmotic potential is
countered by hydrostatic pressure.

51. The initial, final, and change in weights and the Percent Weight Change of
potato cylinders placed in different concentrations of sucrose solutions for
90 minutes.
Sucrose
Initial Weight Final Weight ∆ Weight
Contentration % ∆ Weight
(go) (g) (g - go)
(M)
0 2.7930 2.8600 0.0670 2.40
0.1 2.8373 2.8325 0.0048 0.169
0.2 2.7395 2.5479 0.1916 6.99
0.3 2.6992 2.3307 0.3685 13.65
0.4 2.6900 2.0258 0.6642 24.69
0.5 2.8865 2.1195 0.7670 76.70
0.6 2.8773 3.0325 0.1552 5.39
0.7 2.9200 3.0635 0.1435 4.91
0.8 2.9564 3.0940 0.1376 4.65
0.9 2.8681 2.9964 0.1354 4.72

52. Discussion of Results
0.9
0.8
0.7
0.6
Percent 0.5
Change in
Weight (g) 0.4
0.3
0.2
0.1
0
0 0.2 0.4 0.6 0.8 1 1.2
Sucrose Concentration (in M, moles/L)
Fig 5. Plot of Percent Change in Weight (in grams) vs. Sucrose Concentration (in
M, moles/L).

53. Conclusion
 Experimental data: failed to present the
expected trend and failed to show the
concentration of sucrose where there is
0% ∆ in weight
 Theoretical data would show that the
higher the concentration of sucrose, the
higher the percent change in weight.

54. Discussion of Results
 Theoretically, the sucrose concentration
between 0.2-0.3M should have registered the
zero percent change in weight.