Name ________________________
“Rate of Photosynthesis”
Essential Question: How are living things dependent upon each other and their
environment to meet their energy needs?
Focus Question 1: How do energy and matter transfer through an ecosystem?
Focus Question 2: How do biotic and abiotic factors shape ecosystems?
1. What is photosynthesis?
2. What organisms carry out photosynthesis?
3. What do organisms need to carry out photosynthesis (reactants)?
•
Where do organisms get these reactants?
4. What do organisms that carry out photosynthesis produce (products)?
•
What happens to these products?
5. What is the formula for photosynthesis?
Use the following data to create graphs of the effect of different variables on the rate of
photosynthesis. For all graphs, plot photosynthetic rate on the y-axis – it is the dependent
variable. Do your best to use the entire graph. Label the axes and provide units for each variable.
1. Graph your results from Table 1: The effect of ____________ on the ________________________
2. Based on the graph above, write a complete sentence that summarizes the relationship between
light and rate of photosynthesis. *Be specific in describing the SHAPE of your graph.
3. Graph the data in Table 2:
Title: The effect of ____________________________ on the _____________________________.
4. Based on the graph above, write a complete sentence that summarizes the relationship between
carbon dioxide concentration and rate of photosynthesis.
* When the stomatal factor is equal to one the stomata are completely open.
5. Graph the data in Table 3: (Do not graph the data for stomatal opening.)
Title: The effect of ____________________________ on the _____________________________.
6. Based on the graph above, write a complete sentence that summarizes the relationship between
water and rate of photosynthesis. *Be specific in describing the SHAPE of your graph.
7. Based on table 3, what is the relationship between water intake and stomatal opening?
8. Based on table 3, what is the relationship between stomatal opening and photosynthesis rate?
9. Graph the data in Table 4: The effect of __________________ on the _________________________
10. Based on the graph above, write a complete sentence that summarizes the relationship between
temperature and rate of photosynthesis.
11. How does this graph explain the amount of biodiversity in deserts and the top of mountains?
12. What is the optimal (best) temperature for photosynthesis?
13. The water from the atmosphere is NOT used as a reactant for photosynthesis. However, humidity
greatly affects the rate of photosynthesis. Based on your results in Table 5, explain why humidity
affects photosynthetic rate. (Hint: CO2 enters through the stomata!)
14. Based on table 5, write a complete sentence that summarizes the relationship between humidity and
rate of photosynthesis.
15. Based the data in table 6, which color seems to give the highest rate of photosynthesis?
The lowest rate of photosynthesis?
16. Graph the data in table 7. Plot wavelength on the x-axis and photosynthetic rate on the y-axis. This
graph is an action spectrum of photosynthesis, as it shows the wavelengths at which the process is
most active.
Title: The effect of __________________ on the _________________________
17. Relate the graph above to the fact that most leaves are green. Explain why being green is an
adaptive advantage for plants. (Hint: If you are wearing a green shirt, it appears green because green
light is being reflected!)
18. Summarize: Based upon all your graphs and data, what are the
optimal (best) conditions for photosynthesis? Be thorough!
Collected Data for: Flow of Energy and Matter
“Rate of Photosynthesis”
Table 1: The effect of light on the rate of photosynthesis.
Light Intensity (angstroms)
0
500
1000
1500
2000
Rate of Photosynthesis (O2 ppt/min)
0
58
89
99
106
Table 2: The effect of carbon dioxide concentration on the rate of photosynthesis.
Carbon Dioxide
Concentration
2%
4%
6%
8%
Photosynthetic Rate (O2
ppt/min)
70
93
120
120
Table 3: The effect of water on the rate of photosynthesis. Light intensity = 1500
Water Intake Rate
0.00
0.05
0.30
1.00
Stomatal Opening
Factor*
0.10
0.69
1.00
1.00
Photosynthetic Rate
(O2 ppt/min)
0
20
106
106
Table 4: The effect of temperature on the rate of photosynthesis.
Temperature
5° C
15° C
25° C
35° C
45° C
Photosynthetic Rate (O2 ppt/min)
11
84
106
84
11
Table 5: The effect of humidity on the rate of photosynthesis.
Humidity (%)
0
25
50
100
Stomatal Opening Factor
0.54
0.78
1.00
1.00
Photosynthetic Rate (O2 ppt/min)
47
66
84
84
Table 6: The effect of color on the rate of photosynthesis.
Color
BLUE
GREEN
RED
Rate of Photosynthesis (O2 ppt/min)
44
17
36
Table 7: The effect of wavelength of light on photosynthesis.
Wavelength (nm)
380 (violet)
420 (violet-blue)
460 (blue)
500 (green)
540 (green)
580 (yellow-green)
620 (yellow-orange)
660 (orange)
700 (red)
Photosynthetic Rate (O2 ppt/min)
2
43
21
17
9
19
41
36
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