Effects of Changes in Temperature, pH and Enzyme Concentration on Enzymatic Activities
1. Introduction
Enzymes are biological catalysts that are protein. They speed up the rate of chemical reactions and metabolism in the body of organisms. They are specific in their action that means a certain enzyme will only speed up a certain reaction involving a specific substrate to bring about a specific product. Enzymes work on a key and lock mechanism where substrates are linked to their active sites. Enzymes reduce the activation energy required for reactions thus ensuring that reactions are more efficient in the sense that they use the least possible activation energy. Since enzyme are protein nature, changes in environmental conditions such as temperature and pH affects the structure of the enzyme’s active site and thus the activity of the enzyme which in turn affects the reaction in which the enzyme participates. Equally, the rate of enzyme activity is affected by the relative concentration of enzyme and substrate in the reaction mixture. This experiment investigates how the changes in temperature, pH and enzyme concentration affect the enzymatic activity of catecholase in potato juice extract (Biology 107 Lab Manual, 2011-2012 ed.) The presence of polyphenoloxides (PPO) in fruits and vegetables is one of the causes of change in color. Color is one of the most important attributes of food both for its aesthetic value and for quality. Minimally processed fruits and vegetables are important issues for consumers because of the maintenance of fresh-like quality and natural ingredients of the fruits and vegetables. In food industry, enzymatic browning can be avoided by thermal inactivation of PPO but heat can cause unwanted softening of tissues. Instead, chemical additives have been used to prevent enzymatic browning (International Journal of Food Science and Technology