PHOTOSYNTHESIS Lab Activity
PHOTOSYNTHESIS Lab Activity
PHOTOSYNTHESIS Lab Activity
Objectives:
After working on this exercise, you should be able to:
Procedures
A. Effect of Chlorophyll
1. Select one young variegated leaf of Coleus. Examine and take note of the
areas with chlorophyll. Sketch and label the green and non – non green areas.
2. Boil the leaf 2 – 3 minutes.
3. Remove the leaf, blot it dry and immerse it in 95% ethyl alcohol until the
pigments are extracted.
4. Rinse the bleached leaf with tap water. Place in a petri dish and 2-3 drops of
dilute iodine solution to determine the presence of starch. The occurrence of
photosynthesis is indicated by a bluish – black to purple coloration.
5. Sketch the bleached leaf and label the photosynthetic and non –
photosynthetic portions.
B. Effect of Light
1. Grow two potted bean plants for 1-2 weeks. Place them in the dark for 48-
72 hours.
2. Cover one plant with carbon paper and keep the second plant
uncovered. Expose both plants to light for 6 hours.
3. Detach one leaf each from the covered and uncovered plants. Test for the
presence of starch by adding three drops of iodine solution per leaf.
A. Effect of Chlorophyll
B. Effect of Light
Reaction to starch test: leaf from covered plant: ____________
Leaf from uncovered plant: _________
C. Effect of Carbon Dioxide
Color changes in test tubes with Phenol red
Test tube Before blowing After blowing 20 -30 minutes
after adding
Hydrilla
1
2
3
*outline of chromatogram
RF Values:
Pigment 1 _________________
Pigment 2_________________
Pigment 3_________________
Pigment 4 _________________