|Explore||Background: The rate of photosynthesis is influenced by temperature. Spinach is known to be a cool weather crop. Spinach grows the best when temperatures range between 16 degrees C and 18 degrees C. If the temperature is too cold enzymes will mover slowly to their substrate and the reaction will...|
|Research Question||How does temperature affect the rate of photosynthesis?|
|Predictions||In the range from 10 degrees C to 25 degrees C, it is expected the most photosynthesis will occur around 16 degrees C.|
|Experimental Design||What is our plan? Be sure to include enough detail that another group can replicate our experiment. What variables will we test? What variables will we measure and observe? What variables will we keep constant? How will we record our data?|
|Conclusion||What claim can we make from our experiment? What are possible explanations for our results? How do the data we collected and our reasoning with scientific ideas support our claim? What future experiments could be done to expand on the results of this experiment?|
Hello, Mrs.Holmes, we were just wondering if you can interpret the data, because it was very interesting. Especially for trial 2 when the leaf disks rose and then fell. I feel if we had a better understanding of it, the conclusion could be written better.
I just wanted to say thanks for sharing your research with me! I really enjoyed hearing about your literature search and reviewing your lab report. I hope you've had fun seeing the process of photosynthesis in action through your leaf disk assays; it's pretty incredible that the plants around us are building themselves out of air, sunlight, and water all the time.
Best of luck, and keep tinkering!
Hello Mrs. Holmes, I have sent a revised copy of the lab. Please take a look at it when you have a chance, and feel free to give any advice/feedback.
Hello Mrs. Holmes this is a final rough draft of our lab. Can you take a look at it when you get the chance and give us some feedback? Thank you!
Hello Mrs. Holmes, we ran our last experiment today. It was interesting because, for trial two and three, the leaf disks in the hottest temperature (35C) rose before the leaf disks in the optimal temperature (16C-18C) did. But in the first trial the leaf disks in the optimal temperature rose and the ones at 35C barely rose.
The students did practice the spinach leaf disk assay. I think we have figured out a way to keep temperatures constant for that treatment. They would be measuring the rate of photosynthesis the same way we did with the bicarbonate experiment by measuring the rate. The time at which 50% rise. Then continue on until all leaf disks rise if they want to.
Ann Marie;s article has the temp at 60-650F or 16-180C. It was an article from a gardening journal. We were hoping to find a little better source for the hypothesis. Another group found an article at 250C. At this point, I am curious.
I will be getting the spinach, true winter spinach, from my brother in law an organic vegetable farmer on Wednesday night. He said it is true winter spinach and he will have the name of the variety for me. The spinach is not baby baby, or adult. He called it "teenage spinach."
I hope this helps. I honestly have not figured out how to use this forum and we are progressing along. Thanks for your help.
I ended up printing different ones, with similar information at school. But, can you take a look at my background and see if there are any corrections needed, or anything to be added to it?
Background: The rate of photosynthesis is influenced by temperature. Spinach is known to be a cool weather crop. Spinach grows the best when temperatures range between 16oC and 18oC.1 If the temperature is too cold enzymes will mover slowly to their substrate and the reaction will occur slower.
Although spinach has a cold tolerance, light and CO2 are required during exposure to low temperature in order to attain maximum cold tolerance.2 Usually the higher the temperature, the greater the rate of photosynthesis (due to increased collisions with enzyme and substrate). However, if the temperature is too high, the rate of photosynthesis can decrease. Enzymes involved are sensitive and can denature the active site, which can inhibit proteins' ability to work. CO2 fixation decreases by moderately high temperature stress. The decrease CO2 from inorganic compounds to organic compounds is associated with the inhibition of activation of rubisco.3 Photosynthetic II is the primary site of heat damage to the photosynthetic function. Although, it has been reported that dephosphorylation of PSII in response to heat stress can be considered as a protective mechanism, where the repair process of PSII is done. Overall, adding too much heat to spinach leaves will kill them because it will not be able to perform photosynthesis. Lowering the temperature too much will also kill process of photosynthesis.
From the articles I've found, I formulated this hypothesis.
Hypothesis: In the range from 10oC to 25oC, it is expected the most photosynthesis will occur at around 16oC.
The hypothesis still needs work, because another group found the optimal temperature around 25oC, but I found from 16oC-18oC.
Hello Mrs. Holmes, so we are just going to stick with winter spinach leaves. Also, do you think you can find any articles on the affect temperature has on photosynthesis on spinach leaves, i am still having trouble finding some. Most that i am interested in i have to buy it to read the whole article.
We're setting up the experiment with placing water and the spinach leaves, and a thermometer inside plastic cups and then surrounding it with styrofoam to ensure the temperature is constant. Placing it in temperatures below 60 degrees F, above 65 degrees F and between 60 and 65. (i found that spinach leaves grow best between 60 and 65 degrees F)
How do you suggest we measure the rate of photosynthesis? Maybe with an indicator to see how much glucose was produced, or something to measure how much oxygen was produced? or any other idea.
P.S. It would be good to look up any tips for the search engine you use. E.g. some search engines will let you use * to shorten words and search for more matches. So if you search for "cucurbit*", you will get back results for both "cucurbit(s)" and "cucurbitaceae." In general, start with fewer key terms (not sentences) and add more words when you need to refine your search.
That's really interesting - when you say winter/summer spinach leaves, are you referring to two different varieties of spinach, or just the time at which a single variety is grown?
I would head to Google Scholar to look up the effect of temperature on photosynthesis at the broadest level (all plants) first. Your instructor also mentioned that you have access to the NY state Gale databases; is that through your library? In either case, it would be good to use keywords such as "photosynthesis" and "temperature." Sort your results by "most cited" and you should get the most broadly-applicable and easy to understand scientific papers. You may not be able to find a study on spinach, but that's okay.
If you would like to learn more about how spinach in particular photosynthesizes, you could perform a separate Google Scholar search with "photosynthesis", "temperature", and "spinach." However, you're likely to get more information if you look up what kind of vegetable spinach is. For instance, squash, watermelon, and cucumbers are all "cucurbits," in the scientific family Cucurbitaceae. Plant families end in "aceae." If you find the right plant family for spinach, and perform a search using that word (e.g. "cucurbitaceae"), you should be able to find some papers that use vegetables that have a close evolutionary relationship to spinach, and presumably share some traits with spinach that affect its photosynthetic response to temperature. You can make some predictions about your project based on those studies, and your more general literature search of photosynthesis and temperature.
If you do have different varieties of winter and summer spinach, you might want to look up what the plant breeders did to make those varieties "summer" versus "winter" using Google Scholar.
Hope that helps! Let me know if you need me to clarify anything.
Also, do you know where we can find any articles on the affect temperature has on photosynthesis in winter/summer spinach leaves?
Hello Mrs. Holmes, for our experiment on, we are trying to determine the affect temperature has on the rate of photosynthesis in winter/summer spinach leaves.
Hi Rachel and AnnMarie,
It's so nice to meet you! Apologies for the delayed response. I'm really looking forward to helping you navigate your project. Rachel, my sister is a veterinary technician and a dog trainer, and it is really cool to see her work with animals. AnnMarie, I also used to dance ballet...but not very well Luckily I'm still in a field (Ecology) where the community of scientists loves moving around and getting outside. I am a graduate student at Cornell, and am studying natural plant-insect communities, including how plants use toxins to defend themselves against insect herbivores. I'm particularly interested in how plants try to both outgrow each other in crowded fields - for resources such as sunlight! - and produce hard-to-make toxic compounds at the same time. Previous research suggests doing both is not easy. Since photosynthesis is such a fundamental process, I'm looking forward to hearing more about your project. I think it's easy for all of us to take it for granted, but the ability of plants to harness air, water, and sunlight to "build" themselves is so essential to life - after all, plants are the foundation for our food chain. Looking forward to learning more about your project,
I am Dr. Devesh Shukla, working as a Liaison to coordinate between you and your mentor, and teacher. I am pleased to see your activities in school. Katherine Holmes will be your mentor for this group project. She will guide you through this exciting science quest "Power of Sunlight."