Info
| Explore | What we know: Photosynthesis occurs when there is an adequate supply of CO2 and sunlight, which is absorbed by the photosynthetic pigment chlorophyll inside the thylakoids of the chloroplasts; and cellular respiration happens in the mitochondria most prominently during the night; photosynthesis... |
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| Research Question | If one plant was placed in a constant cold temperature, one was placed at a constant room temperature, and one was moved between cold and room temperature, how would their photosynthesis production (pH) compare? Climate change and natural temperature fluctuation (especially in the Midwest... |
| Predictions | We predict that beads that remain in the fridge will have the lowest pH, meaning that they perform photosynthesis at the slowest rate. If the pH becomes too acidic, the photosynthetic enzymes within the algae beads could denature, rendering them incapable of performing photosynthesis. The beads... |
| Experimental Design | We will compare 3 cubettes, each with 10 algae beads and CO2 indicators at different temperatures. One of our control groups will be at a constant room temperature (26 degrees Celsius), one will be at a constant cold temperature (kept in a refrigerator at 7 degrees Celsius), and our independent... |
| Conclusion | This experiment demonstrated that a plant regularly switching between cold and room temperature environments photosynthesizes at a slightly slower rate than a plant left stationary in a room temperature environment and significantly faster than a plant left stationary in a cold environment. The... |
| About this Project | This project deserves consideration for a Star Project award due to the exceptional dedication and effort demonstrated by the group. Their commitment extended beyond regular class hours, with early morning and throughout-the-day involvement in meticulously switching their algae beads between... |
Updates
Hi MaKenzie!
We finished our experiment! We put 10 algae beads in each of 3 cubettes, and analyzed the effect of drastic temperature changes on photosynthesis. One cubette was kept in a constant cold temperature in the fridge, one was placed at a constant room temperature, and one was moved between the fridge and the room. We ensured that each cubette was equidistant to the light source (8 inches away), and also jostled each cubette every time we checked on it to ensure that there would be no outside variables influencing our results. The cubettes contained CO2 indicator, which allowed us to measure the pH, and thus the rate of photosynthesis for each cubette. We checked on each cubette between every bell across 2 full school days, and recorded our observations and data in a table. We predicted that the beads that remained in the fridge would have the lowest pH, (slowest rate of photosynthesis), those that were kept at room temperature would have the highest pH (fastest rate of photosynthesis), and those that were moved between room temperature to cold temperature would have a pH level in between (average rate of photosynthesis).
We found that that the beads at room temperature and the beads that were moved from room temperature to cold temperature had the same pH of 9.1 at the end of the experiment, meaning they performed photosynthesis with the same efficiency. However, it took longer for the beads that were moved between different temperatures to reach this high pH value, indicating that its rate of photosynthesis was slightly slower than that of the beads in the constant warm environment. Our data also indicated that the beads in the cold environment had the slowest rate of photosynthesis, as the cubette had a pH of 8.7 at the end of the experiment, which was lower than that of the other two environments.
Our data supports our hypothesis that plants placed in warm environments have the fastest rate of photosynthesis, plants undergoing drastic temperature changes have a slightly slower rate of photosynthesis, and plants placed in cold temperatures have the slowest rate of photosynthesis. This is due to the fact that photosynthetic enzymes slow down in the cold, and speed up as the temperature increases.
Overall, we were happy with our findings and the experiment as a whole. We greatly appreciate your time, and the information you provided to help us in our experiment.
Thank you!
ACE Hardware team
Hi ACE Hardware team, I've taken a look at your research question and think that it has a good scientific foundation and motive (climate change and natural temperature fluctuation) and that there is a lot of potential to see some interesting effects of temperature on plant growth through photosynthesis!
Temperature plays an important role in the timing of different developmental and growth processes in plants such as flowering (warmer temperatures) and dormancy (colder temperatures), with cold typically causing a reduction in metabolism (photosynthesis). Rapid temperature drops can also lead to plant tissue damage since the plants may not have enough time to activate some of their defense strategies against cold such as reducing their water content to prevent cells from freezing or increasing their sugar storage which acts as a sort of antifreeze for protection from the cold. This could be an important concept to consider when formulating some experimental predictions, especially for the plants that you plan to keep in cold and those you will move between cold and room temperature conditions.
Have you started thinking about what kind of plants you will be using in your experiment (I know you mentioned you were interested in looking at how temperature fluctuation influences plant growth due to living in the Midwest; will you be using some native plants?) Also, how do you predict plant type might affect photosynthesis at room/cold temperatures, are some better equipped at dealing with cold than others? Do you know what temperature you plan to use as your cold variable since temperatures that are too cold tend to have more detrimental effects on the plants (e.g. rapid leaf browning and shriveling along with potential stem splitting/breakage). Also, how do you plant to measure photosynthesis using pH? Will a higher or lower pH correspond with a higher rate of photosynthesis?
We’ve experimented with spinach leaf disks and the effect of carbon dioxide on them — they can’t conduct photosynthesis without a supply of CO2. We then applied that knowledge to the question of where the mass of trees comes from. CO2 is a vital part of photosynthesis, which provides the energy for the Calvin Cycle that consumes CO2.
If two seedlings were planted in identical containers with equal amounts of soil, sunlight, and water but one in a CO2-heavy environment and the other in an oxygen-heavy environment, will the seedling in the CO2 environment grow faster?
Hey Claire, that's a great question! It makes sense that a seedling would grow faster, or have an accelerated rate of photosynthesis at high concentrations of CO2 since it is one of the drivers of the process. Interestingly, in some species increased CO2 exposure can eventually lead the plant to suppress photosynthesis. This can be due to a few things like the accumulation of glucose and other carbohydrates (products of photosynthesis) which then downregulates photosynthesis through feedback inhibition or a decrease in nitrogen, which is an important component of chlorophyll. Here's a paper that talks in detail about some of the effects of increased CO2 exposure on plant growth! I'll also add it to the files tab if you are unable to access it.
Photosynthesis and Plant Growth at Elevated Levels of CO2
I’m Emily, and I am also a junior! My favorite class at school is psychology. I am a cheerleader, member of the school choir, and copresident of our medical club. My favorite plant is a hydrangea!
Hello everyone!
It is great to hear from everyone, especially the students.
I am serving as a liaison here. I will be helping all of you with your issues and problems.
I am a Botanist and serve as a Professor of Biology at the University of South Carolina Sumter. I love plants! My research is on environmental stress, pathogenic interaction, and other stresses on plant ultrastructure and physiology. I am also a dedicated gardener. I am trying to switch to a plant-based diet as well, and am in the process of learning more about the phytochemicals present in old traditional herbal medications.
I wish all of you a very successful project!
I’m Claire, I’m a junior and my favorite classes in school are AP Bio and Psychology! I play clarinet in marching band and pit orchestra, and am a president of our medicine club. My favorite plants are succulents!
I’m Audrey, and I’m a junior. My favorite thing to do in school is work on the yearbook. Outside of school I dance and I play saxophone in the marching band. My favorite plant is a willow tree!