Photosynthesis lab report

Essay by bluebird8691College, UndergraduateA-, February 2007

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Photosynthesis is a food making process for algae and plants. The photosynthesis process rate varies from different wavelengths and intensities of light. This lab will evaluate the optimal wavelengths and degrees of intensity during photosynthesis when chloroplast is exposed to light. The mixtures of DCPIP with water, PO4 buffer, and chloroplast will be prepared in a number of cuvettes. The cuvettes were tested individually at different wavelengths and intensities to find the optimal rate of photosynthesis by using a spectrophotometer, measuring the greatest change in absorbance. From this experiment, two data charts and four graphs were obtained. The hypothesis was set from graphs obtained in this lab, and the optimal reaction rate was found at a wavelength of 650 nm and an intensity of 50 uEinsteins/m^2/sec. Introduction

Every species on earth needs some kind of energy sources in order to survive. In animal cells, the mitochondria produce ATP from cellular respiration.

However, the plant cells have a different type of center that produces energy- chloroplasts. The main process of photosynthesis is the absorption of light by the pigments. The light energy absorbed is first transferred by exited electrons to reaction centers. Part of the light energy is stored in ATP and NADPH through a series of electron carriers. ATP and NADPH are the energy currency, which are further used for CO2 fixation and photorespiration. (Plant Ecophysiology, 1996). The lab experiment deals with wavelength and intensity, which are the two most important variables in the photosynthesis process. Being easily found in the leaves, chloroplasts are located in plant cells. The photosynthesis process takes place inside the chloroplasts, which are stacked in thylakoids called grana. The area between the thylakoids and the inner membrane is called the stroma (Campbell, 2002). The light reactions of photosynthesis take place in the thylakoid while...