ANATOMY AND PHYSIOLOGY LABORATORY
GROUP MEMBERS NAME: Date:
ACTIVITY NO. 1
OSMOSIS AND DIFFUSION
Objectives:
1. To measure the effects of solute in the process of osmosis.
2. To demonstrate diffusion across a semipermeable membrane
3. To differentiate hypertonic, hypotonic and isotonic environment
Materials:
3 raw eggs
Cellophane (ordinary cellophane used in making ice candies)
1% (w/v) sodium chloride (table salt) solution
1% (w/v) sucrose (table sugar) solution
5% (w/v) starch solution (cornstarch, boil suspension, and allow to cool)
Distilled water (WILKINS OR ABSOLUTE)
Iodine (POVIDINE Iodine will do)
3 250ml beakers (glass container)
One 400ml beaker (glass container)
Yarn/string
Tape measure
Watch glass 5ml pipette (plastic medicine dropper)
Marker
Pencil
Kitchen scale
Methodology:
A. Diffusion and Osmosis in Egg shells
1. Weigh the raw eggs (make sure it doesn’t have cracks). Record the data.
2. Using the tape measure, determine the horizontal and vertical measurements of
the eggs. Mark the ends of the eggs with a pencil. Measurements should be in
millimeters
3. Place the egg in the beaker. Make sure the beakers are appropriately
labeled. Note: there should be 1 egg each) per solution.
4. Pour about 200 ml of solution into the beakers. Beaker 1(sodium chloride). Beaker 2
sucrose solution. Beaker 3 distilled water.
5. Leave the beakers undisturbed in a corner away from direct sunlight and at least
on with constant room temperature for at least three (3) days.
6. On the third day, take the eggs out of the solution and carefully dry them off with
paper towel.
7. Weigh and measure the eggs. Record the data.
BIOCHEMISTRY SY 2019-2020 ACTIVITY 2
B. Diffusion Through a Semipermeable Membrane
1. Soak the cellophane in water for about 30 minutes or until it becomes soft and
pliable.
2. Fill the cellophane half-full with starch solution.
3. Tie the cellophane tightly with the string. Make sure that it is secure and there are
no leaks.
4. Rinse the cellophane gently with distilled water to ensure it is not contaminated
with starch. Set it aside.
5. Fill a 400 ml breaker with 300ml distilled water. Mix it with 3ml of iodine(3 full
plastic medicine dropper)
6. Immerse the cellophane sample into the beaker containing the iodine solution. Let
it stand for 15 minutes.
7. While waiting for diffusion to occur, test the reaction of starch with iodine by placing
a small amount of starch solution in a watch glass ( saucer) and adding a drop of
iodine in it. Observe the color change. Record the results
8. After 15 minutes, observe the colors of the solution in the beaker and in the
cellophane dialysis tubing. Record the results.
OBSERVATIONS:
A. Diffusion and Osmosis in Egg Shells
Eggs in different Initial Final mass (g) Difference % Difference in
solution mass(g) in Mass (g) mass
DISTILLED WATER
Trial 1
NACL SOLUTION
Trial 1
SUCROSE SOLUTION
Trial 1
B. Difference in Measurement of Eggs
Eggs in different
solution Vertical Measurement in cm Horizontal Measurement in cm
Initial Finals Difference Initial Finals Difference
(cm) (cm) (cm) (cm) (cm) (cm)
DISTILLED WATER
Trial 1
NACL SOLUTION
Trial 1
SUCROSE SOLUTION
Trial 1
NOTE:
To make a 1% solution of NaCl , sucrose and 1 gm of sucrose or salt in 100ml water
To make 5% starch solution add 5gms of starch in 100ml water
C. Diffusion through a Semipermeable membrane
SOLUTION Before Immersion After 15 minutes of Immersion
Starch solution in the cellophane
Iodine solution in the beaker
Resulting color when starch was added with a drop of iodine: _
GUIDE QUESTIONS:
1. Give Application of osmosis in the human body and in daily activities.
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2. What is there less blood flow to the brain during a state of “shock’? During and incidence
of shock syndrome, what happens to the blood capillaries?
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3. How does a hemodialysis machine works as a semipermeable
membrane? _ _
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Reference: Josue,P.B.& Ocenar, M.M.M. (2014). Biochemistry for the health sciences
laboratory manual and workbook. Quezon City: C& E Publishing
