Influencing the Rate of Photosynthesis
Purpose:Tofindout how the of presence light and the intensity of it contributes to the rate of photosynthesis
Hypothesis:Develop Your Hypothesis: As the light intensity ______ the rate of
photosynthesis will _______.
(Will their be a certain point where the rate will not increase any more.).
Procedure: (use the right arrow key to advance to the next step)
1. Place the elodea in a beaker containing water and also a bit of sodium hydrogen carbonate-NaHCO3-(0.5%). This is put in as it acts as carbon dioxide.
2. Place the beaker next to a lamp 1centimeter away.3. For one-minute tally/count the number of bubbles
produced.4. Fill in your data on table 1-15. After one minute move the lamp 2cm away from the test
tube.6. Repeat steps 3 and 4.7. Continue this process for the next three minutes at
distances of 4, 8, and 16 cm from the test tube. 8. Record all data on table 1-1.9. Experimentalsteps1-7havebeensimulatedonthenextfive
slides.Advancetothenextslideandrecordyoudata.
Practice counting:
1 cm from the test tube
2 cm from the test tube
4 cm from the test tube
8 cm from the test tube
16 cm from the test tube
Now Graph Your Results
and answer your analysisQuestions.
What would happen if we Increased CO2?
ByusingSodiumBicarbonate?
2 NaHCO3(s) heat Na2CO3(s) + H2O(g) + CO2(g)(9)
Results from actual
LabGroup 5cm 20cm
NaHCO3
5cm 20cm
2 10.5 10
3 67.5 11 80
4 11.5 4.5 15
5 45 13.5 65
6 6 1.5 .5
Period 3:Results from actual
LabGroup
2 3 4 5 6 Class Averages
5cm 13.5 12.5 20 73.5 15 26.9
20cm 4.5 8 16.5 40 7 15.2
5cmNaHCO3 22.5 16 53 112 20 44.7
lAB
5 cm from the test tube
20 cm from the test tube
5 cm + Sodium Bicarbonate
Endforthisactivity
Factors affecting Photosynthetic rates
5cm 10cm 20cm
5:52 7:37 21:00
10:09 11:01 21:00
11:38 15:03 23:35
5:52 7:47 20:00
7:03
6:07
average 8:06 9:31 21:51
DataPeriod1 Averages
Minutes
5cm 8:06
10cm 9:31
20cm 21.51