Report on Osmosis in Human Red Blood Cells for Bio22 Lab. References: Campbell, et. al., Biology Hallare, Student Handbook in Gen. Zoology Part 1

1. Bettina Agnes Lee Josh Christian Protacio
Justin Stuart Tcheng Darla Teylan
OSMOSIS IN HUMAN RED BLOOD
CELLS

2. INTRODUCTION
Human red blood cells function for
transport, and for circulation of oxygen,
nutrients, wastes and other materials
throughout the body. They are enucleated
in order to create more space for
hemoglobin and are mainly found
within the heart and blood vessels
and circulatory system.

3. WHAT IS OSMOSIS?
Movement of molecules from an
area of higher concentration to an
area of lower concentration
through a SEMI-PERMEABLE
MEMBRANE

4. IN A HYPOTONIC
SOLUTION
Concentration of solutes inside
the cell is greater than the
concentration of solutes of its
environment
Result: Cell will increase in size
because solvent will enter the
cell.

5. IN AN ISOTONIC
SOLUTION
The concentration of solutes in
and out of the cell is equal. Water
flows across the membrane at the
same rate in both directions.
Result: Cell will remain the same
size

6. IN A HYPERTONIC
SOLUTION
Concentration of solutes inside
the cell is less than the
concentration of solutes of its
environment
Result: Cell will shrink because
solvent will go out of the cell.

7. HEMOLYSIS
The rupture or destruction of
red blood cells.
*similar to plasmolysis in
plant cells

8. CRENATION
The shrinkage of red blood cells
resulting in crenate margins
Crenate
- Having the margin or surface cut
into rounded scallops

9. OBJECTIVES
At the end of this activity we should be able
to
1. Observe for changes in the shape of
cells
2. Predict the direction of the diffusion of
solutes
3. Understand the reasons for such
phenomenons

10. HYPOTHESES
Null Hypothesis:
No change in the size of the human red
blood cells in different NaCl concentration
solutions
Alternative Hypothesis:
Human red blood cells will change in size in
different NaCl concentration solutions.

11. METHODOLOGY

12. • Microscope
• 3 Glass Slides
• 3 Cover slips
• Ocular micrometer
• Stage micrometer
• Sterile lancet
• 0.07M NaCl solution
• 0.15M NaCl solution
• 0.30M NaCl solution
• Alcohol
• Cotton ball
• Dropper
• Willing volunteer
• Timer
MATERIALS AND
EQUIPMENT

13. 1.
Calibrate the
microscope
PROCEDURE

14. 2.
Label 3 slides
and collect 3
drops of
blood from a
willing
volunteer
PROCEDURE

15. 3. Add a drop of
0.07M NaCl solution
to first slide, 0.15M
NaCl solution to the
second slide, and
0.30M NaCl solution
to the third slide. Miz
the blood and NaCl
solution thoroughly
and smear the
mixture evenly.
PROCEDURE

16. 4. With the
microscope at
400x
magnification,
measure the size
of the red blood
cells every 5
minutes for one
hour. (Use an
ocular micrometer
and compute for
the size using the
calibration factor)
PROCEDURE

17. RESULTS

18. 0.07M
INITIAL VS 60 MINUTES

19. 0.07M
INITIAL VS 60 MINUTES

20. 0.15M
INITIAL VS 60 MINUTES

21. 0.15M
INITIAL VS 60 MINUTES

22. 0.30M
INITIAL VS 60 MINUTES

23. 0.30M
INITIAL VS 60 MINUTES

24. SIZE OF RBC PER CONCENTRATION OF NACL
SOLUTION
Time 0.07 M 0.15 M 0.30 M
Initial 0.015mm 0.015mm 0.015mm
5 minutes 0.015mm 0.015mm 0.01125mm
10 minutes 0.015mm 0.015mm 0.0075mm
15 minutes 0.015mm 0.015mm 0.0075mm
20 minutes 0.015mm 0.015mm 0.0075mm
25 minutes 0.015mm 0.015mm 0.0075mm
30 minutes 0.015mm 0.015mm 0.0075mm
35 minutes 0.015mm 0.015mm 0.0075mm
40 minutes 0.015mm 0.015mm 0.0075mm
45 minutes 0.01875mm 0.015mm 0.0075mm
50 minutes 0.01875mm 0.015mm 0.0075mm
55 minutes 0.01875mm 0.015mm 0.0075mm
60 minutes 0.01875mm 0.015mm 0.0075mm

25. SIZE OF RBC ACROSS
TIME
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
0.07 M
0.15 M
0.30 M

26. DISCUSSION

27. FACTORS AFFECTING
RESULT
NaCl solutions were not exactly
0.07M, 0.15M, and 0.30M
Unequal amount of NaCl solutions
and blood

28. DISCUSSION
A solvent always moves from a higher
concentration to a lower concentration which
equalizes the concentrations of solutes on both
sides.
In the experiment, the RBC’s immersed in
0.07 M sol’n became bloated or hemolyzed
0.15 M sol’n retained their shape and size
0.30 M sol’n shrunk or crenated

29. CONCLUSION
With the data acquired, we can say that,
A) In the 0.07 M slides, the solvent flowed
from outside the RBC to inside the RBC.
Thus, the 0.07 M sol had a lower
concentration of solutes than those of the
RBC’s.
It is a hypotonic solution.

30. CONCLUSION
B) In the 0.15 M slides, the RBC’s showed
no signs of change.
Thus, 0.15 M sol had a similar or same
concentration of solutes like those of the
RBC’s.
It is a isotonic solution.

31. CONCLUSION
C) In the 0.30 M sol, the solvent flowed from
inside the RBC to outside the RBC.
Thus, the 0.30 M sol had a higher
concentration of solutes than those of the
RBC’s.
It is a hypertonic solution

32. REAL LIFE APPLICATION

33. REFERENCES
Campbell Biology, J. Reece et. al, (Tenth Edition)
Oxford Dictionary of English
Merriam-Webster Dictionary

34. Bettina Agnes Lee Josh Christian Protacio
Justin Stuart Tcheng Darla Teylan
OSMOSIS IN HUMAN RED BLOOD
CELLS