1. Arnel, Kimberlyanne, Wendy

2. Motivation
Find how the different spectrums
of light affect the rate of
photosynthesis in plants.
 If a plant is placed under a green colored light, less
photosynthesis occurs compared to other colors on
light spectrum.

3. What is photosynthesis?
Photosynthesis is the process of
converting solar energy into
chemical energy.
 Chloroplast a & b
 e- transport chain

4. Materials
 3 Beakers
 3 Petri Dishes
 Green, Blue, and Red Food Coloring
 5 Cuvettes
 Water
 Chloroplast Solution
 DPIP
 6.5 pH Phosphate Buffer
 Spectrophotometer
 Light Source

5. Methodology
 3 cuvettes containing solution were placed
in separate beakers
 Covered with petri dish lids filled with
red, blue, and green food coloring
 1 cuvette was placed and covered under a
large bin.
 1 cuvette was placed under the normal
lighting

6. …
 Every five minutes for twenty minutes, the cuvettes
were taken from the beakers and placed into the
spectrophotometer to measure the transmittance of
light.

7. Setup

8. Percent Transmittance vs. Time
Minutes Control Blue (%) Red (%) Green (%) Dark (%)
(%)
0 21.8 35 55.8 50.6 17.2
5 20 65 50.2 53.2 16
10 20.2 71.6 70.4 53.6 16.4
15 19.8 70.6 62.4 53.2 16
20 19.6 70.8 69.8 53.8 16.2

9. Graph
Rate of Photosynthesis
80
70
Light Transmittance (%)
60
50
Blue
40
Red
30
Green
20
Dark
10
0
5 5 10 15 20
Time (minutes)

10. Blue & red light
 Chloroplasts contain pigments named
chlorophyll a and chlorophyll b which
absorb photons from the sunlight.
 The pigments absorb blue and red
light best.

11. Green light
Green light is reflected
By reflecting the green, little to
no sunlight is absorbed.

12. Dark
Decreased due to no light being
absorbed.
Light is needed to create ATP and
power photosynthesis.

13. Photosynthesis 