The Influence of Variation of Light Intensity in the Rate of Photosynthesis in Hydrilla Verticillata1, and Effects of Polarity and Molecular Weight in Separation of Photosynthetic Pigments

[pic 1]

The Influence of Variation of Light Intensity

in the Rate of Photosynthesis in Hydrilla verticillata1,

and Effects of Polarity and Molecular Weight

in Separation of Photosynthetic Pigments[pic 2]

Fritz Jay T. Dalawampu

Neil Christian R. Sanjorjo

Botany 1

Introduction to Plant Science Laboratory

T-3L

November 4, 2014

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        1A scientific paper submitted in partial fulfillment of the requirements in General Botany 1 Laboratory under Mr. Marlon P. Rivera, 1st Semester, 2014-2015.

ABSTRACT

                The purpose of the experiment conducted is to find out if the varying light intensities affect the photosynthetic rate, and if the polarity and molecular weight of the chromatogram solvent affect the separation of the photosynthetic pigment. The procedure involved controlling the light with regards to the Hydrilla verticillata. On the other hand, the procedure involved in the separation of chlorophyll pigments includes the soaking of filter paper with pigments on the beaker with a chromatogram solvent. The results of the experiment resolved that the higher the light intensity, the faster photosynthetic rate will occur. On the other experiment, it showed that the less soluble and polar the pigment is, the further the movement of the pigment will be and the higher retention factor it has. With the help of these experiments, we can conclude that the varying light intensities do really affect the rate of photosynthesis in the Hydrilla verticillata, and the less soluble the pigment is the further movement it will go with because it has lesser molecular weight.

INTRODUCTION

The variations in the light intensities really affect the photosynthetic rate, but first, the term “photosynthesis” will be defined. Photosynthesis is a very vital process in the environment which takes place in the chloroplasts of plants that contain a pigment named chlorophyll; it also produces triose phosphate by using the water and carbon dioxide that leads to the release of a sugar and oxygen which is a by-product of this process. Being unknown to the majority, it has been already proven by many researchers that light is a necessity by many plants to perform the indicated process. This is due to the fact that light intensity is one of the key factors that greatly have an impact on the rate of photosynthesis. Moreover, these lights will make up the chlorophyll that will then absorb the light from the sun.

To further prove this, the Bubble Counting Method is introduced as an experimental model. It is consisted of the common plant used in such experiments also known as Hydrilla. Aside from being common, the Hydrilla sprigs are used since they are aquatic plants. The hypothesis of this experiment mainly focuses that the varying light intensities in the environment greatly affect the rate of photosynthesis, to be more specific, the higher the amount of light in the environment, the faster the rate of photosynthesis will occur.

In accordance with photosynthesis, the rate of photosynthesis will then also be defined. For many students, the rate of photosynthesis is just the speed of how photosynthesis produces oxygen which is a very important element to many of us, but for scientists and researchers, it is not only the speed of how oxygen is produced but also it is the rate of photosynthesis to release a by-product within the shortest span of time. For instance, there are also previous studies and experiments regarding this showing the same and exact results. Meanwhile, the main objective of this study and experiment is to determine if the increase in light intensity hugely affects the rate of the photosynthesis.

Now, the next experiment that will be tackled is about the separation of photosynthetic pigment through paper chromatography, but the terms chromatography, chlorophyll, and retention factor will then be also defined. The paper chromatography is one way of knowing some types of a chemical mixture. The type of paper to be used here is necessary and must be modified or specified such as the filter paper. This is also known as a separation technique to identify different coloring agents in food, ink, or pigments.

Next is the chlorophyll. Being the pigment produced in the chloroplast, chlorophyll is the one responsible for the absorption of sunlight that uses the energy to synthesize a certain molecule originating from carbon dioxide and the water. Since we are talking about chlorophyll, it is unknown to many that the chlorophyll has still four pigments such as chlorophyll a, chlorophyll b, xanthophylls, and carotenoid. The chlorophyll a is the one with the yellow-green color; the chlorophyll b with the green color; the xanthophylls is the one with the yellow color, and the carotenoid with the orange color. Here, the chlorophyll a is the most common in all photosynthesizing plants, but we can still compare it with different plants since plants absorb wavelengths of different length and frequency.