DiscussionHypothesis 1Overall, as the substrate concentration increases, the enzymatic activity increases up to 70% of the solution, where the enzymatic activity begins to stabilize. The curve is polynomial due to the fact that the activity of the enzyme increases exponentially as the concentration of the substrate increases; further evidence of this is the fact that the gradient graph is constantly changing. The polynomial curve is shown because up to 70% (the saturation point); this is because there are more casein substrate molecules that can successfully collide with the renin enzyme molecule, therefore increasing the reaction rate. However, once it reaches 70% concentration, the enzyme becomes saturated, meaning there are no active sites for the substrates to fill, which leaves the casein (milk) molecules suspended in the curd; the saturation point of this curve was located at 6.5x 10-3 seconds. This was clearly evident in some visual results of the practice, where we could see that there was still some milk that could be siphoned off when the curd was poured. Therefore, even if we added more casein substrate, the enzyme activity curve would still flatten, once again indicating that all or most of the active sites of the renin enzyme were full. Furthermore, the class average curve shows a similar trend, as the curve flattens out, at 70% but with an enzymatic activity of 5.3 x10-3 seconds. This indicates that, although the saturation point is the same, it was considerably lower than our results, which may indicate sources of systematic error in practice design. The control for both curves was the beaker with a 0% concentration of substrate, which produced no enzymatic activity, since there were no substrate molecules for... half the paper... to run the stopwatch itself. Alternatively, we could also exclude milliseconds from calculating the results. This would therefore eliminate any reaction time and consequently make the data more reliable and accurate. To conclude, one major random error was the idea that the renin enzyme solution was mixed inconsistently with the casein: as if we were almost encouraging the curds to form. This meant that because each molecule of renin and casein had more kinetic energy, they were more likely to collide. As a result, the rate of the reaction would increase slightly. Although we tried to constantly stir the mixture, it was difficult to keep it continuous throughout both drills. Therefore, to keep the stirring more constant, we could use a magnetic stirrer, in order to make the kinetic energy used to stir the mixtures a controlling factor.