The effects of enzyme and substrate concentration, temperature and pH on catecholase activity were determined in this experiment. To attain these results, potato extract (Solanum tuberosum) was mixed with catechol and exposed to different environmental conditions, then placed in a spectrophotometer to measure and record the different absorbance readings at a 420nm wavelength. It was found that catecholase activity was optimal with a pH of 6.6 and in temperatures between 27-30 ∘C. The enzyme and the substrate concentrations affected the rate of reaction by increasing it.
Introduction:.
Enzymes are a kind of protein that catalyze reactions by bonding to specifically shaped active sites thus lowering the energy reaction level which in turn speeds up the reaction. Catecholase or polyphenoloxidase (PPO), an enzyme found in various fruits and vegetables, converts catechol to benzoquinone and water in the presence of oxygen. (Mitchell et al., 2002) Fruits and vegetables use this process to protect themselves from rotting and bacteria. (Wegener, 2002).
In this experiment we focused on the effect enzyme concentration, substrate concentration, temperature, and pH, had on the enzyme activity of catecholase (in this experiment potato juice was used). We hypothesized that changing the temperature and pH from within the optimal range would disrupt the reaction. We also hypothesized that because enzyme and substrate concentrations in a reaction are proportional to each other, the reaction will occur at a speed proportionate to the amount of enzyme/substrate present.
Methods and Materials:.
In this experiment four different environmental and concentration factors were tested and compared by taking readings of absorbance on a spectrophotometer set at 420nm (note: all readings were taken at this setting). .
To find the effect of enzyme concentration on the rate of the reaction (Experiment 1), four test tubes were prepared as "blanks- with 0, 0.
