Photosynthesis and Cellular Respiration Lab Report

Photosynthesis and Cellular Respiration Lab Report Abstract In these experiments, the main focus was to represent photosynthesis and cellular respiration in a non-complex way so one can learn how these two important processes are necessary for organisms. To model photosynthesis, we used spinach leaves as live cells to be used to show how other complex plants use photosynthesis and how having an abundant source of carbon dioxide can benefit the plant. We noticed that the spinach samples which were placed in the bicarbonate solution went through photosynthesis faster than the samples which were placed in only water. Baking soda acts as an carbon dioxide source due to its chemical composition, therefore placing it in the water which is supplied to a specific plant will allow it to go through photosynthesis faster and allowing it to grow even more. This is one of the reasons why many gardeners use carbon dioxide sources to use in their gardens so that their plants are able to thrive quicker than it would with just a normal supply of water. As for the cellular respiration lab, three different variables were used to test the rate of cellular respiration depending on how the organism is structured. The three variables included germinating seeds, nongerminating seeds and glass beads. One could see that the germinating beans which needed more carbon dioxide to process cellular respiration was the one that gave off the most oxygen which was measured in the microrespirometer. One can conclude that non-living organisms do not need cellular respiration due to the fact that they are not living whereas more complex organisms will give off more oxygen as a byproduct as they are using more carbon dioxide as well as ATP to drive their cellular respiration. Both of these labs allowed one to understand each of these complex yet simple processed which drive the metabolism of both animal and plant organisms. Materials and Methods Photosynthesis Materials • • • • • • • • • Baking Soda Liquid Soap 2 plastic syringes Living leaves (spinach) Hole Puncher 2 clear plastic cups Timer Light Source Pipette In one clear cup, place 100 mL of water and in the other, place 100 mL with a.2% bicarbonate solutions. Using a pipette, place a drop of liquid soap on the surface of each cup. Label each cup with its specific solution (with co2 and without co2). Using a hole puncher, cut out 10 circles of spinach for each cup. The leaf surface should be smooth. Afterwards, remove the piston of each syringe and place the circles at the bottom. Insert the piston without crushing the leaves and draw out the gases it may contain. Afterwards, obtain 25 mL of the solution into the syringe and once again remove the gases. Once all disks start to sink, place them in their respective plastic cup. Put the light source over each cup and time how long it takes for the disks to float Cellular Respiration • • • • • • • • • • • • • • Germinating seeds Non-Germinating seeds Glass beads pipette thermometer water bath beaker food coloring 15% solution KOH Absorbent cotton Non-absorbent cotton Cups glass tubes Microrespirometers In 3 glass tubes, place absorbent cotton on the bottom and add a drop of 15% KOH solution. Place non-absorbent cotton over and place 3 beans or beads in each. Get a water bath at 22 degrees celsius while preparing for this experiment. in 3 cups, place the warm water inside to act as an insulant. Cover each glass tube with a microrespirometer and allow it to sit in the cup of water. Place a drop of food coloring at the tip and time how long as well as the distance the drop goes as time goes on. Results Hypothesis for Photosynthesis Lab: The disks that are placed in the baking soda solution would float faster than those that were in the water solution. Hypothesis for Cellular Respiration Lab: The Germinating beads would give off more oxygen than the non-germinating and glass beads. The results of the Cellular Respiration and Photosynthesis Lab are in the following spreadsheet: Conclusion These labs can be related to how cell energetics work, which are the driving forces of not only cells, but more complex organisms too. The two main processes include photosynthesis and cellular respiration, which were both processes that were represented through these two experiments. The first part of the lab included photosynthesis and used spinach samples to represent typical plant samples. Since spinach was a live specimen, it was a perfect resource to use to indicate how photosynthesis works in plants as it is an on-going process. Our hypothesis at first was that the spinach circles that were placed in the baking soda solution would float more faster than those that were placed in a simple water solution. We had in our knowledge that baking soda was a carbon dioxide source, therefore when placed along with the spinach circles, it would act a benefit to them. The baking soda would allow the spinach circles to go through photosynthesis much quicker. Before experimenting, the disks were placed in syringes and were drawn out any gasses they may contain. This is due to the fact that oxygen and other gases are trapped in the mesophyll layer of the plant, therefore to allow them to sink, these gases must be removed. The data we took showed that the numbers of disks floating in the baking soda solution were more and floated faster than those in the water solution. It took almost 30 minutes for the last disks to finally float in the water solution, indicating that the process of photosynthesis was slower. As the samples began to go through photosynthesis, the oxygen given off allows them to float to the surface. For the cellular respiration lab, many factors were involved which would create the perfect environment to test the amounts of oxygen given off for each variable as a result of cellular respiration. The cotton and KOH solution that were placed in the glass jar were used to only measure the oxygen given off and not the water. The water would be absorbed through the cotton. The respirometers that were placed on each glass jar made sure that no oxygen would be released and would go up the tube. The food coloring acted as an indicator, it would be sucked in through the tube as oxygen was escaping. The glass tubes were placed in the same water temperature, which was around room temperature, so that the samples membranes were not physically damaged. After collecting the data, one can see that the germinating beans were the ones that went through cellular respiration the fastest since they are living organisms about to become a plant. The non-germinating beads did not go through it as fast since it did not need a supply of oxygen. Lastly, the glass beads cellular respiration process was very little, since they did not need ATP or oxygen to “survive”.