Download Effect of Salinity on Respiration

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.
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
Slopes
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
Results
Peas in
pure H2O
slope: -0.00099248
Results
Glass
beads in
pure H2O
Slope: -0.00001622
Difference in Slope (kPa/sec)
Results
Level of Salinity (% NaCl)
Discussion and Conclusion
•
According to data…
pure water produced
the best results
o our hypothesis was
correct
● Reducing water (the
medium for H+ and P
gradients) = reducing
cell respiration
o
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)...?