Effect of Salinity on Respiration by Karen, Leah, Max, and Patrick

Problem How does the salinity of the peas’ germination environment affect its respiration?

Background ●Cellular respiration is driven by H+ and phosphorus gradients ○ They allow for energy to be formed. We know the equation for respiration is: glucose + O 2 → energy + H 2 O + CO 2

Hypothesis We think that: o Peas grown in pure water environments will have the greatest growth and the most efficient respiration rates. o Introducing salt into the peas’ germination environment may also affect H+ and phosphorus gradients within the peas, lowering respiration as a result.

Procedure 1. Cover peas in towels soaked in 0.01%, 0.02%, or 0.03% saline solutions. Cover one set of peas in towels soaked in pure water as well. Allow them to sit for 24 hours. 2. Find the volume of 25 peas from each treatment and find corresponding volumes in glass beads. 3. Prepare the test tubes. Collect data using Vernier Pressure Sensors. 4. Find slopes of all graphs

Results Pure H2O crossed out 1 gram NaCl (0.01%) Green (ex) Burgundy (gb) 2 gram NaCl (0.02%) Navy (ex) Olive (gb) 3 gram NaCl (0.03%) Rose (ex) Periwinkle (gb)

Results ExperimentalControl Pure Water % % % Slopes

Results Peas in pure H 2 O slope:

Results Glass beads in pure H 2 O Slope:

Results Difference in Slope (kPa/sec) Level of Salinity (% NaCl)

Discussion and Conclusion According to data… o pure water produced the best results o our hypothesis was correct ●Reducing water (the medium for H+ and P gradients) = reducing cell respiration

Sources of Error Pressure sensor error Stopper not on tight enough 1 day old peas vs decade old peas Not enough germination time Keeping peas wet

Extensions At what salinity does respiration cease? How do floods/tsunamis affect crop growth? Does germination in salty environments affect other aspects of the peas (size, lifespan, photosynthesis rate, taste)...?