Will An Increase In Concentration Of Copper (II) Ions Decrease The Rate Of Photosynthesis From Algae? Research Question Will an increase in concentration of copper (II) ions decrease the rate of photosynthesis from algae, taken from the “Golf beach”? Hypothesis Heavy metals can decrease plant metabolism, including photosynthesis, in a number of ways. By increasing the concentration of copper (II) ions, the growth of algae would decrease. The acclimation of the algae is formed by the abiotic stress of copper (II) ions in the accumulation of solutes prepared by the researcher.
The growth of algae would be reduced drastically by copper (II) ions due to the complexation of the metal. The metal would inhibit the activity of enzymes directly by binding to protein sulphydryl groups, producing deficiency of essential ions and in return, substituting the essential ions reduced. Due to the interaction with water and ions balance, the metal would reduce the growth in algae, elicit oxidative damage of membranes and consequently inhibit physiological processes and decrease bio-production by inhibiting photosynthesis.
Controlled Variables – Temperature (naturally controlled) – Light intensity (naturally controlled) – Carbon dioxide concentration (naturally controlled) – Time (controlled by using a stopwatch) Independent Variable – Concentration of copper (II) sulphate solution Dependent Variable – Rate of photosynthesis Apparatus and Materials Apparatus Quantity/Amount Electronic balance (±0. 0005g) 1 100ml beaker 1 Filter funnel 1 L-shaped connecting tubes 1 Tube-connector 1 Drop of dye 1 30cm ruler (±0. 05cm) 1 1M CuSO4 1 small bottle (at least 250ml) Wet sea algae 20g Sea water 400ml Stopwatch (±0. 005s) 1 Method 1. Collect algae samples from the “Golf Bay” and place them in Set up the experiment as directed by the subsequent steps, 3-7. 3. Where does the drop of dye go at this point?
4. Wait for 3 minutes to have enough time for the Cu (II) ions to diffuse into the algae cells. 5. Measure how far away is the drop of dye away from the starting point.
6. Wait for 20 minutes. 7. Take down the distance between the drop of dye and the starting point. 8. Repeat the experiment 4 more times with 30%, 45%, 60% and 75% copper (II) sulphate concentrations. 9. Group the data. Expected Errors 1. Salt concentration may vary when different concentrations of copper (II) sulphate are used because the portion of sea water becomes different. 2. Some oxygen gas may dissolve into the solution when it floats to the surface, decreasing the distance between the drop of dye and the starting point. 3. Random misbehavior of organisms.