The Power of Photosynthesis

may be fed. Scope and Limitation of the Study The study has its own limitations. To determine if the color of light affects the amount of oxygen released through the process of photosynthesis by Hydrilla, only the red, blue, yellow and green component color of light were chosen. Due to the unavailability of colored light bulbs, simulation of such using red, blue, yellow and green cellophane as wrappers is done.

Since there is no available instrument to measure the amount of oxygen released by the Hydrilla plant in the process, we will simply measure the length of rise of the test tube in 10- minute exposure to light. Definition of Terms: HYDRILLA(Hydrilla verticillata) or water thyme is a submersed plant. LIGHT refers to the artificial light coming from the overhead projector. PHOTOSYNTHESIS is the process by which autotrophic organisms convert light energy to chemical energy in the form of glucose.

REFERENCE POINT refers to the mark in the test tube that corresponds to the tip of the funnel at the end of the 10th minute exposure of the set-up to light. RED LIGHT, BLUE LIGHT, YELLOW LIGHT, GREEN LIGHT refer to the components of artificial white light. Red light is simulated when the beaker is wrapped with red cellophane; blue light when the beaker is wrapped with blue cellophane; yellow with yellow cellophane; and green light with green cellophane. VOLUME OF OXYGEN RELEASED corresponds to the length measured from the base of the test tube till the marked reference point expressed in millimeters.

Chapter II Review of Related Literature Plants are green because they reflect green light more than any other part of the color spectrum, therefore if

a plant is only exposed to green light it will reflect more than if it were placed under a red light thereby making photosynthesis less efficient. The colors that plants use during photosynthesis come from both ends of the light spectrum. The plants use the greens and yellows during germination and it reflects it giving plants its color. It uses the other end with the blue and red by absorbing it and using it to create ATP energy and grow sufficiently.

The formula for photosynthesis is H2O + CO2 + light = O2 + C6H12O6 + ATP. PH is not a factor. The quality of light could effect the process. A strong bright light is going to help the process while a dim, low light will slow the process as light is part of photosynthesis ( Meyer R and Donnet L, 2000) The study made by Anastasia Rodionova, Cassidy Davis and Sara Cucciniello on the effect of different colored lights to photosynthetic rate showed that all the pigments at peak absorbance showed violet/blue light at the highest level, orange/red light as the second highest, and yellow/green having the lowest level of absorption.

They hypothesized that photosynthesis was affected by the light absorption rate. Chapter III Methodology Research Design The effect of the colors of light on photosynthesis of Hydrilla that will be measured as volume of evolved oxygen will experimentally determined. Five set-ups will be done with three replications each. The control set-up will the Hydrilla exposed to natural light. The experimental set-ups will be exposed to red, blue, green and orange light. The source of light will b the light from the overhead projector. The light

exposure will be done at 20-minute interval.

The variable to be observed in this study will be volume of gas emitted. The following variables will be set as constants: time of exposure to artificial light, distance of the set-up from the light, volume of water, type of plant, intensity of the light, size of the beaker, amount of Hydrilla, temperature of water and the chemical properties of water. Procedure Ten identical beakers will be filled with equal amount of water. Hydrilla with a length of 175 mm will be placed inside the cup of the funnel. The funnel with Hydrilla will be slowly placed in an inverted position inside he beaker with water. A 10-mL test tube filled with water will be inverted into the stem of the funnel as shown in Fig. 1. Fig. 1 . The set up of the experiment. It will be made sure that no air is trapped inside the test tube. The set up will be placed on top of the overhead projector as light source. Cellophane will be used to vary the color of light coming from the overhead projector. Three photosynthesis set-ups will be exposed to natural light for 20 minutes. The beaker will be removed from the top of the overhead projector.

Then the volume of oxygen gas obtained through water displacement will be measured and recorded. The procedure for the natural light of determining photosynthesis activity will be repeated with the other beakers using either red, blue, orange and green cellophane which will be used to vary light color. Fig. 2 shows the exposure of the hydrilla to different colors of light. Fig. 2 Light exposure BIBLIOGRAPHY

1. Busche, Frederick (1972) Principle of Physics. 2nd Edition, McGraw Hill Book Company, New York 2. DepEd,Science and Technology IV (2004) Book Media Press Inc. Philippines 3. Meyer R. ,Donnet L. and Hacket T. (2002) McGraw Hill Science National Geographic Society, New York City 4. Villamarin N (2003) Science- High School Com General Science, Bookman Inc. , Philippines 5. http. //www. juliantrubin. com 6. http. //www. wordpress. com Photosynthesis of Hydrilla verticillata exposed to Different Colors of Light A Research Proposal Presented to Dr. Melchora B. Lamorena Presented by Adelma S. Topacio Nonalie P. Pichuela Nilda T. Acero Connie B. Villanueva Kristina Cassandra S. Fabregas Danilo E. Vilas 12 November 2010