Leaf and Photosynthesis
The purpose of this experiment was to determine the rate of photosynthesis in different concentrations of a Bicarbonate solution. My Hypothesis was that if you placed the spinach disks in the highest concentration of bicarbonate then that is where photosynthesis would happen the fastest. We cut out equal disk from a plant leaf and placed half in water and the other half a bicarbonate solution.
We then used a syringe to carefully extract the bicarbonate solution, and then we removed the air out of the syringe and created a small vacuum within the syringe and later released the vacuum. This process was repeated until enough leaf disks’ air has been swapped with the solution and the leaf disks submerge into the solution. We repeated this method again with water instead of bicarbonate and put them under the same intensity of light.
The results obtained by the experiment support my hypothesis; the solutions containing the higher concentrations of bicarbonate had faster rates of photosynthesis than those with less. The solution with 2% underwent photosynthesis at an average rate of 8:50 seconds, followed by the 1% at 11:02 seconds and the 0.5% at 11:32 seconds. The highest concentration solutions underwent photosynthesis several minutes before those containing lower concentration. In conclusion my hypothesis was not false and indeed the leaf disks in the beaker containing the highest concentration of bicarbonate underwent photosynthesis the quickest.
Photosynthesis is process of obtaining energy from light a reaction which without there would be no life. A very simple reaction explained by this formula 6CO2 + 6H2O + Energy –> C6H12O6 + 6O2 ,(Urry et al 2014) We try to understand photosynthesis and the factors that affect it. As we look into photosynthesis we see that factors such as light intensity, different types of plants and concentration levels play a role in rate of photosynthesis (Spilatro 1998). We’ve set up this experiment to understand how different
concentration levels of CO2 can affect the rate of photosynthesis, and I have hypothesized that in higher concentration level of a bicarbonate solution should yield a faster rate of photosynthesis.
In this experiment we used a hole punch to cut out several disk shape leaves from spinach. We then separated the disks into equal amounts and place one half into water and the other half in to a bicarbonate solution. We then used a syringe to carefully suck up some bicarbonate solution and remove the plunger end of the syringe, then put your finger on the other end of the syringe and then put the leaf pieces into the part of the syringe that you took out. Put the plunger back and flip the syringe upside down getting rid of the air. Encase the tip of the syringe with your finger and pull on the other end to create a vacuum, hold for a little bit and then let it go. Do this over until the air has been substituted solution and they sink into it. Reuse this method but instead of bicarbonate use water instead. Put the leaf disks into a beaker with bicarbonate and the other one with water and place them under the same light source.
In my hypothesis I stated that the leaf disks placed in the beaker containing high concentration of bicarbonate would experience that highest rate of photosynthesis. The results obtained from this experiment support this hypothesis as the solution with the highest concentration over went photosynthesis the fastest out of all of the bicarbonate solution. The results strongly support my hypothesis as I notice a trend that was the rate of photosynthesis was fastest from highest concentration to lowest concentration so it wasn’t a coincidence that the results turned out the way it did.
A problem I encounter while conducting this experiment was time management. The last solution took longer than forty plus minute so we did not include that solution with our results. Another problem I faced was trying to get large enough spinach to get better disk samples. Some sources of error would be due to the small size of the sample spinach, the leaf disks may have been punched to close to the leaf veins. And we weren’t certain how many disks were supposed to cut out to make sure we had enough testing materials. Things we could’ve done to make sure the experiment went smoothly was grab a larger sheet of tin foil to guarantee no light got in and be more accurate when it came to timing the disks times.