Photosynthesis
Research Question How does carbon (IV) oxide concentration affect the rate of photosynthesis?
Background The biological process through which green plants make food is called photosynthesis. For photosynthesis to occur, three factors must be present; light, carbon (IV) oxide, and water. During photosynthesis, carbon (IV) oxide molecule is broken into carbon and oxygen atoms. The end product of photosynthesis is glucose and oxygen gas. The process depends on light to produce energy (Dogutan et al. 3183). The process of photosynthesis can be summarised by the following chemical equation below;
From the above equation, six molecules of carbon (IV) oxide and water in the presence of light produce a single molecule of glucose and six molecules of oxygen. There is a positive association between carbon (IV) oxide concentration and the rate of photosynthesis. Increasing carbon (IV) oxide concentration will increase the rate of photosynthesis, and thus more oxygen gas will be produced. In this experiment, the production of bubbles (oxygen) will be assumed to represent the rate of photosynthesis.
Procedure 1) Launch the simulator using the link below; https://scratch.mit.edu/projects/ 133475453/embed 2) Adjust the brightness to 20 k/Lux and set the color of light to white by pressing writer (W) as shown by the image below; 3) Adjust the carbon (IV) oxide concentration to 300 ppm and record the number of bubbles produced at 60 seconds. 4) Repeat step 3 above two more times and record the data. 5) Repeat step 3-4 two using various concentration of carbon (IV) oxide.
Data
raw data table
Carbon (IV) oxide Number of bubbles concentration (ppm) Trial 1 Trial 2 Trial 3 300 8 8 8 400 18 17 18 550 20 21 20 700 22 22 22 900 24 24 24 1000 26 26 26 1300 28 28 28
The average number of bubbles Trial 1 + Trial 1 + Trial 1 T he average number of bubbles = 8+8+8 Average current (300 ppm) = =8
I used some processes to calculate the average bubbles produced, as recorded in table 2 below;
Processed data table
Carbon (IV) oxide concentration The average number of (ppm) bubbles 300 8 400 18 550 20 700 22 900 24
Analysis Based on the data from table 2 above, it is clear that as the carbon (IV) oxide concentration increases, the process of photosynthesis (number of bubbles) also increases. When the carbon (IV) oxide concentration was 400 ppm, the average number of bubbles was 18. As the carbon (IV) oxide concentration increased to 900, the average number of bubbles was 24. The data above can be plotted as shown by the graph below;
Carbon concentration vs number of bubbles y = 0,0226x + 5,5 R² = 0,7524
Number of bubbles 0 225 450 675 900
Carbon concentration Figure 1: Graph of carbon concentration vs. number of bubbles Based on the graph above, there is a direct relationship between carbon concentration and the process of photosynthesis (number of bubbles). As the concentration increases, the rate of photosynthesis (the number of bubbles) increases. The co-efficient of the above graph; R 2 = 0.7524 R= 0.7524 R = 0.86 The R-value is 0.86, confirming the strong positive association between carbon (IV) oxide concentration and the process of photosynthesis.
Conclusion From this experiment, it can be concluded that there is a strong association between carbon (IV) oxide concentration (ppm) and the rate of photosynthesis (bubbles produced). As the process of photosynthesis continues, oxygen will be released as bubbles. As the concentration of carbon (IV) oxide increases, more oxygen gas (bubbles) will be produced as a by-product of photosynthesis.
