By: Haley DeLeon, Alyssa Cantrell and McKenzie Schumacher
In this photosynthesis lab experiment we tested the rate of photosynthesis. We tested different variables to see if they could change the rate of photosynthesis. If you add more drops of the dilute soap solution to the bicarbonate solution
In the experiment we had to sink the leaves' disks in the solution so that they do not contain any more oxygen so that they don't float. This is why we conduct the vacuum so that we can extract all of the oxygen from them so that when we perform the lab the light will allow the disk to produce sugars and oxygen through photosynthesis so that the leaves will begin to float to the top. How ever long it takes the leaves to float that is the rate of photosynthesis.
The Materials needed are:
Procedures:
t hen the rate of photosynthesis will occur slower.In the experiment we had to sink the leaves' disks in the solution so that they do not contain any more oxygen so that they don't float. This is why we conduct the vacuum so that we can extract all of the oxygen from them so that when we perform the lab the light will allow the disk to produce sugars and oxygen through photosynthesis so that the leaves will begin to float to the top. How ever long it takes the leaves to float that is the rate of photosynthesis.
The Materials needed are:
- hole punch
- 3 leaves
- syringe
- 2 beakers
- Sodium Bicarbonate Solution
- Water
- Dish Soap
- pipettes
- watch glass
- sun
- grow station
Procedures:
- Get 10 leaf disks by punching holes in the same leaf
- Put the 10 leaf disks into the syringe with solution of sodium bicarbonate and a drop of soap solution into the syringe.
- Replace the plunger and push out most of the air, but do not crush your leaves.
- Create a vacuum by covering the tip of the syringe with your finger. Draw back on the plunger.
- Release the vacuum so that the solution will enter the disks. It may take a few times to get the disks to sink.
- Once they have sank, you can put them back into the sodium bicarbonate solution and expose the disks to light
- Place another set of disks into a control beaker that contains only water.
- Record the number of disks floating at the end of each minute, swirl the disks to dislodge any that may get stuck to the beaker or to each other. The experiment should continue until all of the disks are floating.
- Repeat for 2 variable groups and 1 control group.
Data Table: Graph: Graph Justification: The reason we chose to use a line graph is because we wanted to see the rate of change for the disks of leaves and we wanted to see it at a specific time. Therefore we chose to use a line graph because we can now compare the rate of photosynthesis at a specific time for all of the variables. By this graph we can tell when the rate of photosynthesis occurred and how long it took for the disks to float. The estimated time for 50% of the leaves to be floating for the first variable is 4 minutes and 30 seconds. The estimated time for 50% of the leaves to be floating for the second variable is at 8 minutes. Conclusion: Our hypothesis If you add more drops of the dilute soap solution to the bicarbonate solution Then the rate of photosynthesis will occur slower was correct because in our first variable we we only added 1 squirt of the solution and the rate of photosynthesis happened at 1 minute. When we added a second squirt of solution for our second variable the rate of photosynthesis happened at 3 minutes. Therefore the rate of photosynthesis occurred slower when we added more drops of solution. The estimated time for 50% of the leaves to be floating for the first variable is 4 minutes and 30 seconds. The estimated time for 50% of the leaves to be floating for the second variable is at 8 minutes. With the first variable at 10 minutes we had 7 leaves floating. With the second variable at 10 minutes we had 9 leaves floating. Some of the errors we were faced with in conducting this experiment was it took a lot of time to punch the holes out of the leaves. The temperature outside could have effected it too because we had to do our experiments on different days. We also had a teacher error because she left the solutions to sit too long overnight so it could have messed with our data. What can be improved is the amount of time we have to do it and having the leaves as a control because some people didn't even know what type of leaves they were playing. Also maybe teaching us what the questions mean before answering them would help us conduct the experiments better. Analysis Questions: Which solution, water or baking soda solution, caused the disks to rise the fastest? Why? The baking soda caused the disks to rise the fastest because the bicarbonate solution serves as carbon sources for the photosynthesis taking place. Since it serves as carbon the leaves will start to float because it is releasing oxygen into the leaves which will them cause them to float. Water does nothing to leaf because no chemical reactions take place because it is not releasing energy and carbon which will make the leaf float. How is photosynthesis an essential process for life? Photosynthesis is an essential process for life because it helps the plants get energy from the sun and transform it into food so that they can live and survive. When comparing the ET50 across treatments describe the relationship between ET50 and the rate of photosynthesis. The ET50 for the first variable was 4 minutes and 30 seconds. The ET50 for the second variable was at 8 minutes. The rate of photosynthesis for the first variable was 1 minute and the rate of photosynthesis for the second variable was at 4 minutes. As the rate of photosynthesis goes up the ET50 goes down. Therefore as more disks begin to float the time it takes for 50 percent of them to float decreases. As more of them start to float it takes less time to get 50 percent of them to float. | |