Michael Castelli Keegan Bauman Potato Lab Dr.Peano Block 1 Introduction: Potatoes are just your average food; they have been around for as long as the human race can remember.In this lab we will make them be a prime example of osmosis, which is a transport mechanism.
In this lab the problem being tested was what environment affects the mass of the potatoes the most. The independent variable is the environments used salt, water and iodine solution. The dependent variable is the mass of the potato after being exposed to the environment for 5 days.
The control was a potato in no specific environment, meaning it is just sitting in air, no salt and no water/iodine solution. If the potato is exposed to a specific (hypotonic/hypertonic) environment then the mass will increase/decrease because the cell will grow or shrink due to the environment exposed to. Experimental Design: The groups being testes are the hypotonic environment (water and iodine), hypertonic environment (Salt) and the control which is just the potato in just the beaker. The time the potatoes stay in each environment is 5 days.
One potato is in 300mL of water and iodine solution, another is in 300mL of salt and the last potato is just in air. The potatoes are all fully peeled with no skin. The potatoes are in 3 different beakers with saran wrap over the top of each beaker. Materials: 3 potatoes Potato peeler 3; 500mL beakers 300mL of salt 300mL water 50 drops of iodine Saran wrap Safety goggles Triple beam balance Procedure: 1. Gather materials above 2. Put on goggles 3. Be safe 4. Peel three potatoes over garbage 5. Take mass of each potato 6. Record 7.
Put three potatoes in three different beakers 8. Leave one potato in just the beaker (control) 9. In another beaker put 300 mL of water in with 50 drops of iodine (hypotonic environment) 10. In last beaker put 30mL of salt ensuring potato is covered. (hypertonic environment) 11. Put saran wrap over all the beakers 12. Make sure the beakers are sealed 13. Let potatoes sit in environment for 5 days 14. Take potatoes out of environment after five days 15. Take mass of each potato 16. Record 17. Record change in mass 18. Observe 9. See if hypothesis was true 20. Write lab Data: Mass of Potato in Environments | Control (Nothing) | Hypotonic Environment (Water and iodine) | Hyper tonic environment (Salt) | Starting mass | 129. 6g| 135. 5g| 144. 1g| Ending mass | 128. 6g| 150. 8g| 102. 2g| Change in mass | -1g| +15. 3g| -41. 9g| Mass of Potato in Environment (In Grams) Weight in Grams Environment Results: The results did not have any outcome that was not expected. The control changed only a single gram in mass, the hypertonic environment grew by 15. 3 grams.
On the chart above it is below the graph because the starting mass was taken, then the mass after being in the environment was taken, and the result was -15. 3g hence the reason it appears to be negative. The hypotonic got lost 41. 9g of mass. Conclusion: The results that were taken were clear. The hypothesis was correct, based on the environment the potato was in it either grew or shrunk because it was exposed to the (hypotonic/hypertonic) environment. The results are valid because there were no variables in the experiment and also the results were ones that were expected.
In the hypertonic environment the potato grew (as it was expected to) and in the hypotonic environment it shrunk (as it was expected to). The potatoes were expected to do so because when a cell is in a hypertonic environment water tends to flow into the cell, while in a hypotonic environment the water flows out of the cell. This was proven in this experiment. There were no changes to the procedure made. There will be no changes to the procedure if the experiment is replicated again.