Effects of Temperature on Rate of Cellular Respiration

1. Effects of Temperature on Rate of Cellular Respiration Problem: Is there an ideal temperature for peas/organisms to grow in as seen through cellular respiration? Angeline S., Kavinda W., and Ashwini N.

2. Background • Hypothesis: The higher the temperature, the higher the rate of cellular respiration; likewise the lower the temperature, the lower the rate of cellular respiration. • The peas that we have used are autotrophic. They use cellular respiration to create energy from glucose, which uses O₂ and creates CO₂. • In higher temperatures, atoms and electrons are able to move faster, thus creating a higher rate of reaction as the necessary molecules are more likely to meet. This increases the rate of cellular respiration. The rate of cellular respiration, a combination of glycolysis, oxidation of pyruvate, Krebs cycle, and ETC, which rely on electron movement and enzymes, will be increased.

3. Procedures • Temperatures: 1◦C, 15 ◦C, 25 ◦C • These temperatures are reasonable for what the peas normally grow in • Tested: 2 day 25 germinating peas, non-germinating peas, glass beads with the same volumes in each condition • 1◦C: put in ice bath and added salt • 15 ◦C: put in ice bath, cold water, and added salt • 25 ◦C: put on hot plate until it reached 25, then took it off • Put 3 tubes for each trial in cardboard holder with thermometer in beaker of trial’s temperature. • Kept temperature consistent

4. 25 ˚ C 1 ˚ C 15 ˚ C

5. Analysis Recalibration of data: We subtracted the rate of the glass beads from each trial because the rate should be 0. This subtracts the error of changing pressure from change in temperature.

6. Conclusion • Germinating seeds are in the process of growing and therefore undergo cellular respiration faster than non-germinating seeds. • Our non-germinating seeds are mostly dormant and do not consume as much energy as the growing seeds - therefore respiring at a slower rate. • An increase in the temperature will cause an increase in the rate of cellular respiration. Cellular respiration decreases as temperature decreases.

7. Conclusion • There is an optimal temperature for pea growth. Peas, according to our data, support the fact that high temperatures make reactions occur more quickly. • Possible errors: Maintaining temperature of apparatus & loose stoppers • Will certain temperatures denature enzymes or inactivate cellular respiration all together? • Is there any relationship with the size of the seed itself to the rate of respiration?