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