Effect Of Light Intensity On Photosynthesis

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Photosynthesis is the process that plants use to convert light energy from the sun into chemical energy for other organisms’ activities. The two stages responsible for this process are Photochemical reactions (Light reactions) and Biochemical reactions (Calvin cycle). The light reactions consist of two enzymatic protein complexes, Photosystem II and Photosystem I, in the thylakoid membrane of a chloroplasts that use light to reduce molecules to power the electron transport chain. Photosystem II contains a chlorophyll with an optimum wavelength of 680 nanometers that uses the light energy absorbed to excite electrons from the chlorophyll to a higher energy level while using some of the energy absorbed to pump hydrogen ions into the thylakoid membrane (Khan Academy). As water is being oxidized, the electrons stripped are being used to power the electron transport chain, transferring electrons from Photosystem II down to Photosystem I while releasing a biproduct of oxygen. The electrons in Photosystem I are also excited by light to a higher energy state reducing NADP to NADPH. The hydrogen ions that have been pumped into the thylakoid membrane are used for ATP synthase. To fully grasp photochemical reactions in photosynthesis, three experiments were conducted. The first experiment tested the effects light intensity has on the reaction rates of photosynthesis. H1: The lowest light intensity will yield the optimal rate for photosynthesis. H01: The different light intensities
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