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 + O2 → energy + H2O + CO2
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.
Procedure1. 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
ResultsPure 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
Experimental Control
Pure Water -0.0009248 -0.00001622
0.01% -0.0005208 -0.0001455
0.02% 0.0002371 0.0003736
0.03% -0.0004478 -0.0002568
Slopes
Results
Peas in pure H2O
slope: -0.00099248
Results
Glass beads in pure H2O
Slope: -0.00001622
ResultsD
iffer
ence
in S
lope
(kP
a/se
c)
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)...?