| Explore | Plants require sunlight, water, and carbon dioxide to go through the process of photosynthesis. |
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| Research Question | How does the temperature of water affect the rate of photosynthesis in spinach leaves? |
| Predictions | The rate of photosynthesis will be the greatest in warm water for spinach leaves. |
| Experimental Design | Materials: -baking soda -liquid soap -6 plastic syringes -spinach leaves -hole punch -thermometer -ice chest -6 clear plastic cups -timer -43 watt light source -deionized water -warming bath -refrigerator -ruler Procedure: We were testing different water temperatures and their effect on photosynthesis. We tried to replicate the Power of Sunlight experiment, but we included a cold water sample (5 degrees Celsius) and a warm water sample (39 degrees Celsius), along with a room temperature water sample (24 degrees Celsius). To get the temperature for the cold water, we chilled the solution and water constant overnight, then placed those two cups in an ice chest for the remainder of the experiment. To get the temperature for the warm water, we used a warming bath and placed glass beakers into the warmed water, then placed the solution and water constant—in plastic cups— into the beakers. We set up lamps with 43 watt bulbs with the rims 12 centimeters above the bottom of the plastic cups and started the timers. Before this, we used a thermometer to see the exact temperature of each solution. |
| Conclusion | In this experiment, we began by testing how water temperature could affect the rate of photosynthesis in an aquatic plant, but after a few tests and reviewing our results we came to the conclusion that photosynthesis occurs differently in aquatic plants than in other plants which is why none of the leaves would float. We then used the same test, but tested kale. Unfortunately, kale would not cooperate with our test therefore we decided to try spinach for an accurate test. After using the spinach, we came to the conclusion that photosynthesis happens at a faster rate in warmer water. In the cold water, it took more than 30 minutes before a leaf began to float showing us that cold water slows down the rate of photosynthesis. In the room temperature water, it took one minute longer than the hot water to get all ten disks to float. therefore, there isn't that much of a difference, but we can then conclude that as temperature increases so does the rate of photosynthesis. Photosynthesis in warm water is faster because at hotter temperatures more CO2 is available, and this can explain to us why the disks in the without CO2 cup floated as well. If we would want to do future experiments to expand our results, we could use a different plant and compare with the results we got with the spinach. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Mother of Mercy High School |
| Session | Fall 2017 |