Introduction
Components that enhance the rate at which chemical reactions that place are referred to as enzyme (Lehninger, Nelson, & Cox, 2008). Through the reduction of the amount of activation energy that is necessary for a successful completion of a reaction, enzymes manage to reduce the time and resources needed to complete the reaction (Cooper, 2000). The activity of a given enzyme is, usually, affected by the level of different parameters such as temperature, pH levels, concentration of the enzyme and substrate concentration (Eed, 2012).
Enzymes work best within a given range of values for each of these factors and deviation from these values results in a reduced enzyme activity. pH level is the quantity of hydrogen ions that are present in the solution. Any enzyme requires a narrow range of pH to realize optimal activity. This range is referred to as optimal pH. Levels of pH that are beyond the optimal levels result in the alteration of the shape of the enzyme resulting in reduced enzyme activity. The alteration is mainly due to the disruption of the bonds that make the active site of the enzyme (Eed, 2012). Understanding the effect of pH on the enzyme reactions may help in providing reactions with the optimum pH level for maximum product formation.
It was hypothesized that if the pH level of the substrate and the enzyme is altered then the amount of product that is formed will be altered. The purpose of the study was to determine the effect of altering pH level on the activity of an enzyme.
Results
The intensity of the color was highest pH 6 at 0 minutes and pH 7 at 10 minutes and lowest at pH 12. There was an increase in color intensity as pH increased from pH 2 (2) to pH 7 (5) at 0 minutes and up to pH 6 at the 10th minute. At 0 minutes, there was a reduction in color intensity from 5 at pH 7 to 1 at pH 12 as shown in Table 1 below. Color intensity also declined from the highest (5) to the lowest (1) at the 10th minute.
Discussion
The activity of any given enzyme will shoe extreme sensitivity to changes in pH when all the other condition are set at the optimal levels. A reduction in the pH levels may result in a decreased affinity of the enzyme for its substrate. From the results, the optimum pH for the enzyme under study is pH 7. This is indicated by the pH where the reaction gave the best color intensity. Reduction in color intensity in pH levels that are lower than this optimal pH may have resulted from a reversible reaction involving deionization or ionization of R groups of the amino acids that are in the active site of the enzyme. This change in charges of the amino acids results in ineffective configuration of the active site resulting in poor enzyme-substrate interaction.
The results obtained in this study are in agreement with results from previous studies. In a study conducted by Frankenberger and Johanson (1982) on the effect of pH on the stability of enzymes in the soil. The stability of soil enzymes such as acid phosphatase, urease, phosphodiesterase and alkaline phosphatase was seen to depend highly on the pH of the soil. Similarly, phosphofructokinase obtained from mouse and frog skeletal muscles showed extreme sensitivity when small changes in pH were applied (Trivedi & Danforth, 1966).
The results obtained support the proposed hypothesis. Increasing pH increased color intensity from 2 to 7 increased from 2 to 5 and continued increase decreased the intensity to 1. It can thus be concluded that shifts in pH have a crucial role in the determination of the amount of products that are formed from an enzymatically catalyzed reaction.
Reference List
Cooper, G. M. (2000). The Cell (2nd ed.). Sunderland (MA): Sinauer Associates.
Eed, J. (2012). Factors Affecting Enzyme Activity. ESSAI, 10(1), 47-51.
Frankenberger, W. T., & Johanson, J. B. (1982). Effect of pH on enzyme stability in soils. Soil Biology and Biochemistry, 14(5), 433-437.
Lehninger, A. L., Nelson, D. L., & Cox, M. M. (2008). Lehninger principles of biochemistry (4th ed.). New York: WH Freeman.
Trivedi, B., & Danforth, W. H. (1966). Effect of pH on the kinetics of frog muscle phosphofructokinase. Journal of Biological Chemistry, 241(17), 4110-4114.
Vasudevan, D. (2007). Textbook of Biochemistry for Dental Students. New Delhi: Jaypee Brothers Publishers.
