| Explore | Photosynthesis is required for plants to survive and function. Photosynthesis is a cycle and it cut up into two parts; light reactions and the Calvin cycle. A plants color is derived from the sun and its wavelengths. What about photosynthesis gives plants their color? Why are plants green/ different colors? How does a plant's color affect how photosynthesis occurs in it and its rate of occurrence? |
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| Research Question | How do different color lights affect photosynthesis? We thought about what different environmental factors could possibly influence the rate of photosynthesis in plants. We also focused on what we could test in the lab easily and accurately with materials that were available to us. Light reactions occur in the thylakoids and the light being absorbed by the pigments affects the rate of photosynthetic reactions. Therefore, different color lights could alter the light reactions of photosynthesis in some way. |
| Predictions | The possible outcomes of our study are the number of leaf disks floating in each cup, based on how the leaf disks absorb light through colored cellophane. Our explanation is that the different colors will absorb different specific amounts of light, altering how photosynthesis occurs in the disks and how quickly it occurs. |
| Experimental Design | Our plan was to test how different color lights affect the rate of photosynthesis. We did this by placing five cups of baking soda (.2%) under a light, each cup having 10-12 spinach leaf disks in it and covered with different colored cellophane (red, yellow, clear, green, and blue). We left the cups under the light for a period of time to see how many leaf disks floated. We recorded data every two minutes. We tested the colored cellophane and how, in turn, colored light affects photosynthesis. We kept the baking soda amounts as a constant. We recorded our data in a table, and then translated our results on a graph to display our findings visually. |
| Conclusion | Different color lights absorb different amounts of sunlight and light energy which affects photosynthesis. On the "Absorption Spectra of Photosynthetic Pigments" figure, it shows that wavelengths demonstrate how much light is absorbed at the peak of its curve. Our data supports that that different colored lights did, in fact, affect the rate at which photosynthesis occurred in the leaf disks, however, certain colored lights didn't react the way we expected them to. For example, the blue light was thought to absorb more light in order for photosynthesis to occur the fastest when the light shining through the yellow cellophane actually had one of the fastest rates of photosynthesis in the leaves. Future research includes using different colored lights, rather than cellophane coverings and check on our plants more often so that we can get the best data possible. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Arthur L. Johnson High School |
| Session | Fall 2017 |