Effect of Light Intensity
In this experiment, different distances of a light source were tested in order to measure the effects on photosynthesis. DPIP was added to the active chloroplasts in order to test the activity of the electron transport chain within the light reactions of the photosynthetic process. The rate of color change of the DPIP depends on the rate of excitation of the chlorophyll molecules, which is indirectly measured through each sample’s absorbance. The control in this experiment was the chloroplasts that were kept in the dark, which gave a baseline to compare the other distances to. The hypothesized result was that the furthest distance would be the most effective, and absorbance would decrease as the light became closer. The results supported the hypothesis and showed that the three distances all yielded a relatively similar and that all the absorbances were in fact lower than the control group. The results also showed that as the light was moved further away from the chloroplasts the DPIP was reduced faster, producing a lower absorbance.
Effect of Light Wavelength
In this experiment different colors of light were tested in order to see which caused the photosynthetic process to be the most efficient. Discs made of spinach leaves were deoxygenated and placed in beakers with different wavelengths of light in order to measure which wavelength produced the most oxygen the fastest. This experiment was controlled by placing the beakers under various colors, including green although it is known that the color green is reflected by chlorophyll. The hypothesis for this experiment was that the white light would be the most effective and this was most definitely proven true by the data. It was found that white light was the most effective, followed by blue (450 nm) and then red, green and dark (700 and 520 nm) all did not produce enough oxygen to make the discs float at all. This makes sense...