Abstract - The purpose of this experiment was to determine what variables affect the rate of photosynthesis. The variable tested was the pH level of the “environment” and this was tested using leaf discs from a plant. By testing the leaf discs in different pH levels of two, four, six, eight, and ten, it was found that the rate of photosynthesis was at its highest in a pH of six. It was also found that the rate of photosynthesis was at its second highest at a pH of eight and at its third highest at a pH of ten. The lowest photosynthesis rates were found to be at a pH of two and four. Therefore, photosynthesis works best in a more neutral environment where the pH levels …show more content…
At 0:00, there were no discs floating; at 0:30, there were seven discs floating; from 1:00 to 2:30, all ten discs were floating. In a pH 8 solution, the rate of photosynthesis was the second highest. At 0:00, there were no discs floating; at 0:30, there were six discs floating; at 1:00 and 1:30, there were nine discs floating; and at 2:00 and 2:30, all ten discs were floating. In a pH 10 solution,the rate of photosynthesis was the third highest. At 0:00, there were no discs floating; at 0:30 and 1:00, there were five discs floating; and from 1:30 to 2:30, there were eight discs floating. In a pH 2 solution, the rate of photosynthesis was the fourth fastest. At 0:00, there were no discs floating and from 0:30 to 2:30, only one disc was floating. In a pH 4 solution, no discs were floating in any of the time intervals. It was concluded that photosynthesis of spinach leaves was at its highest rate at in a pH solution between six and ten, with pH 6 causing the highest rate. Therefore, the rate of photosynthesis for the spinach leaves is at its highest when in an environment that isn’t too acidic and is around a neutral, or somewhat basic, environment. Some percentage errors of this experiment would include the possibility of some discs getting squashed or harmed when hole punched, some discs being cut out of a major vein of the leaf, and not performing the …show more content…
It was also found that the rate of photosynthesis was at its lowest, if at all, in a pH solution of four and below. Therefore, it is clear that in order for photosynthesis to take place, the environment needs to be within the pH level of six and ten, otherwise the process cannot take place or hardly does (at least in the spinach leaf case). For future experiments, it would be wise to test multiple types of plants to determine whether or not most plants are best suited for photosynthesis in an environment with a pH level between six and ten. Also, to make this experiment more reliable and accurate, the rate of photosynthesis should be tested multiple times with the same experiment so that more data can be collected. By doing each of these, it would be possible to match certain plants with the exact pH levels that cause the rate of photosynthesis to be at its highest