Effect of temperature on rate of photosynthesis
RQ: Does varying temperature (±0.05 oC) affect moles of glucose produced (±0.02 mol)?
Variables:
Independent Variables:
Temperature
Unit: oC
Range: 5 oC, 15 oC, 25 oC, 35 oC, 45 oC
Dependent Variable:
Moles of Glucose produced
Unit: mol
Uncertainty: ±0.02 mol
Variables
Why does it have to be
controlled?
Different pH values can
affect enzymatic activity in a
plant thus affecting amount
of glucose produced
Different CO2 concentrations
can affect enzymatic activity
in a plant thus affecting
amount of glucose produced
How to control?
Varied light intensities can
influence enzymatic activity
in a plant thus altering
amount of glucose produced
The plant was under a
constant light intensity. It
was kept at a constant
distance
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
0
0.632
1.02
1.61
0.395
0
0.695
1.22
1.41
0.639
0
0.466
1.45
1.46
0.718
0
1.09
1.27
1.86
0.592
0
0.847
1.30
1.36
0.596
pH
CO2 Concentration
Light Intensity
The plant had a constant pH
of 7 throughout the
simulation.
The plant was under a
constant CO2 concentration
of 100 μmol
Data:
Temperature
(oC)/Glucose
produced at
25 seconds
5
15
25
35
45
Processed Data:
Mean Data:
Temperature (oC)
5
15
25
35
45
Mean moles of glucose produced
0
0.746
1.25
1.54
0.588
Standard Deviation:
Temperature (oC)
5
15
25
35
45
Standard Deviation
0
0.236
0.155
0.202
0.119
Graph:
Mean moles of glucose produced (±0.02 mol)
1,8
1,6
1,4
1,2
1
0,8
0,6
0,4
0,2
0
0
5
10
15
20
25
30
35
40
45
50
Results and Analysis:
From the graph and data collected, we can infer that the relationship between moles of
glucose produced and temperature is a peculiar one, in the sense that it increases from 0 oC to
35 oC, then decreases rapidly from 40 oC onwards.
The simulation does act as a good model for the real rates of photosynthesis provided the
living system to which it is compared is properly controlled and the measurements are precise
and reliable. The standard deviation values are also very low compared to their means
indicating consistent data.
The chemical reactions that combine carbon dioxide and water to produce glucose
are controlled by enzymes. As with any other enzyme-controlled reaction, the rate of
photosynthesis is affected by temperature. At low temperatures, the rate of
photosynthesis is limited by the number of molecular collisions between enzymes
and substrates. At high temperatures, enzymes are denatured thus explaining the
results attained.
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https://sites.google.com/site/biologydarkow/photosynthesis-model-with-variable-sample-sizes