Personal interest in the investigation:The reason why I chose to explore this topic is becausebotany was always my area of interest as I have always been previously workingon such projects during my school career as a student. I have always beeninterested and amazed by the sea and its oxygen productivity as I have alwaysbeen taught that the ocean is the lung of the earth. Algae have differentpigments that can photosynthesise in different depths where differentwavelengths of light are available. Research Question: Is there adifference between photosynthetic rate in the plant Ludwigia palustris when exposed to different light colors? Hypothesis: When Ludwigia palustris is exposed todifferent light colors, it will photosynthesis differently, the highest rateexpected under normal light and lowest rate under green light. Explanation:The highestlevel of photosynthesis is when normal light is turned on and when thecombination of different wavelengths is present while it is known that thechlorophyll will reject green light and the level of photosynthesis istherefore low. Background ResearchPhotosynthesis:Photosynthesis is the most important chemical reactionconducted in plants, algae and certain bacteria in order to transfer energyfrom light energy or in other words sunlight energy to chemical energy.
Thisprocess happens as green plants contain chlorophyll which attracts the sunlightand is used to convert water carbon dioxide and other minerals into energy richorganic compounds and oxygen that we breathe in everyday. There are two typesof photosynthetic processes and they are oxygenic photosynthesis and anoxygenicphotosynthesis. Oxygenic photosynthesis is the one explained previously, themost common and is seen in plants, algae and cyanobacteria. During oxygenicphotosynthesis, light energy transfers electrons from water (H2O)to carbon dioxide (CO2), which produces carbohydrates. In this transfer, the CO2 isreduced, and the water becomes “oxidized,” or loses electrons.Ultimately, oxygen is produced along with carbohydrates.
On the other hand,anoxygenic photosynthesis uses electron donors other than water. The processtypically occurs in bacteria such as purple bacteria and green sulfur bacteria.”Anoxygenic photosynthesis does not produce oxygen — hence the name,” saidDavid Baum, professor of botany at the University of Wisconsin-Madison. “Whatis produced depends on the electron donor. For example, many bacteria use thebad-eggs-smelling gas hydrogen sulfide, producing solid sulfur as abyproduct.”Though both types of photosynthesis are complex, multistep affairs,the overall process can be neatly summarized as a chemical equation. Oxygenicphotosynthesis is written as follows: 6CO2 +12H2O + Light Energy ? C6H12O6 +6O2 + 6H2OFigure 1: “Photosynthesis.” Khan Academy, Here, six molecules of carbon dioxide (CO2)combine with 12 molecules of water (H2O)using light energy.
The end result is the formation of a single carbohydratemolecule (C6H12O6, or glucose) along with six molecules each of breathableoxygen and water. Similarly, the various anoxygenic photosynthesis reactionscan be represented as a single generalized formula: CO2 +2H2A + Light Energy ? CH2O+ 2A + H2O Wavelengths:In photosynthesis, the sun’s energy is converted to chemicalenergy by photosynthetic organisms. However, the various wavelengths insunlight are not all used equally in photosynthesis. Instead, photosyntheticorganisms contain light-absorbing molecules called pigments that absorb onlyspecific wavelengths of visible light, while reflecting others.
The set ofwavelengths absorbed by a pigment is its absorption spectrum In the diagrambelow, you can see the absorption spectra of three key pigments inphotosynthesis: chlorophyll a, chlorophyll b, and ?-carotene. Theset of wavelengths that a pigment doesn’t absorb are reflected, and thereflected light is what we see as color. For instance, plants appear green tous because they contain many chlorophyll a and b molecules, whichreflect green light.