Data Sheet: Activity – Photosynthesis and Respiration
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Name
Course
Date
Activity Data Code
Procedure I – Net Photosynthesis Rates – 100% Illumination
Complete the tables below using your data and information found under the Background tab (see the Summary of Needed Formulas section)
Leaf
Sample
Type
Illumination
Level
Oxygen
Concentration
Change Data (ppm)
Elapsed
Time
(s)
Oxygen
Change Rate
(ppm/s)
Sun-
Adapted
100%
Shade-Adapted
100%
Leaf
Sample
Type
Illumination
Level
Carbon Dioxide
Concentration
Change Data
(ppm)
Elapsed
Time
(s)
Carbon Dioxide
Change Rate
(ppm/s)
Sun-
Adapted
100%
Shade-Adapted
100%
Observations and Questions
[1] How is chlorophyll involved during photosynthesis?
[2] What are enzymes? What role do they play in biological and chemical reactions?
[3] How might differences in enzyme concentrations affect rates of photosynthesis and respiration?
[4] Show your oxygen change rate calculation for the Sun-Adapted data run.
[5] Show your carbon dioxide change rate calculation for the Shade-Adapted data run.
[6] Review the chemical reaction for photosynthesis and then carefully examine your results from Procedure I. Do your results support the relationship between oxygen and carbon dioxide shown in the chemical reaction? Explain. Cite your results as part of your explanation.
[7] Using your results for change in oxygen concentration as a reference, discuss whether your results from Procedure I confirm research findings about differences in the amount of chlorophyll production for sun-adapted and shade-adapted leaves.
[8] What is the difference between photosynthesis rate and net photosynthesis rate? Which rate are you determining in this procedure? Explain.
[9] Explain why (or why not) you would expect respiration to occur when the illumination is 100%?
Procedure II – Respiration Rates – 0% Illumination Data Run
Complete the tables below using your data and information found under the Background tab (see the Summary of Needed Formulas section)
Leaf
Sample
Type
Illumination
Level
Oxygen
Concentration
Change Data (ppm)
Elapsed
Time
(s)
Oxygen
Change Rate
(ppm/s)
Sun-
Adapted
0%
Shade-Adapted
0%
Leaf
Sample
Type
Illumination
Level
Carbon Dioxide
Concentration
Change Data (ppm)
Elapsed
Time
(s)
Carbon Dioxide
Change Rate
(ppm/s)
Sun-
Adapted
0%
Shade-Adapted
0%
Observations and Questions
[10] Sample Calculation: Show your oxygen change rate calculation for the Sun-Adapted data run.
[11] Sample Calculation: Show your carbon dioxide change rate calculation for the Shade-Adapted data run.
[12] What would be the photosynthesis rate if you measured it at 0% illumination in Procedure II? Explain your answer. Cite your results from Procedure I to assist with your explanation.
[13] Cite your results for the change in carbon dioxide concentration in Procedure II as a reference and compare the rates of cellular respiration for sun-adapted and shade-adapted leaves. Explain the biological principles/bases underlying this comparison.
Procedure III – Low-Light Net Photosynthesis Rates – 15% Illumination
Complete the table below using your data and information found under the Background tab (see the Summary of Needed Formulas section)
Leaf
Sample
Type
Illumination
Level
Oxygen
Concentration
Change Data (ppm)
Elapsed
Time
(s)
Oxygen
Change Rate
(ppm/s)
Sun-
Adapted
15%
Shade-Adapted
15%
Observations and Questions
[14] Sample Calculation: Show your oxygen change rate calculation for the Sun-Adapted data run.
[15] Based on the data you collected in Procedures I (100% illumination) and III (15% illumination), which system of leaves produces the most oxygen: Sun-adapted or shade-adapted? Explain how your results support your answer.
[16] Are your results from Procedure II and Procedure III consistent with research findings that there are differences in chlorophyll production and enzyme activity between shade-adapted leaves and sun-adapted leaves? Explain your reasoning. Cite your results from Procedure II and Procedure III to support your explanation.
