The enzyme then releases the newly formed product, remaining unchanged and ready to catalyze another reaction (Campbell, Reece, 2002).
The enzymatic activity of catecholase is responsible for tissue browning in fruits and vegetables. This enzymatic activity causes the formation of unstable and highly reactive o-quinones, which subsequently react with themselves, proteins, or amino acids, to form brown, black, or red heterogeneous polymers (Paul and Gowda, 2000). The substrates of catecholase in this experiment are catechol and oxygen. Catechol is oxidized to produce benzoquinone, and oxygen is reduced to form water, according to the following equation (Albisu, King and Kozlov, 1989):
Catechol 12O2 -------- benzoquinone H2O
The four factors that were tested in this experiment all play key roles in determining the rate at which an enzyme catalyzes a reaction. When enzyme concentration increases, the reaction rate will increase due to more active sites available to facilitate the reactions (Dixon and Webb, 1958). When substrate concentration increases,