Enzyme Peroxidase Lab Report

Mohammad AlSafwani
Ms. Erin Floyd
Biology 1111
19th March, 2015
Determining the Properties of an Enzyme
Abstract
Enzyme peroxidase is essential in any cell metabolic reaction as it breaks down the harmful hydrogen peroxide to harmful products in the body. The report analyzed its effect on changes in temperatures by determining the optimum temperatures and the effects of its reversibility. Through the method of extracting the enzyme by blending it with potato tissue in phosphate buffer, the effects were analyzed on the effect of the dye guaiacol and the activity measured under different temperatures. The optimum temperature was obtained at 22.20C and above this temperature, the enzyme was denatured. Conclusively, increase in temperature increases

the activity of the enzyme up to the maximum level, and further increase leads to the denaturing of the enzyme.
Introduction
For any chemical reaction to proceed within a cell, activation energy is required to cause and complete this process.

This is made possible by the use of enzymes. Enzymes essentially work within the cells and their ability determined as a result of their specificity brought about by the shapes from the amino acid sequences (Daniel and Danson 2740).
The enzymes have active sites on their surfaces to allow the binding of a substrate through the help of coenzymes to form enzyme-substrate complex. The chemical reaction thus converts the substrate to a new product then released and the catalytic cycle proceeds.
Many factors, for example, pH and temperature affects the way enzymes work by either increasing the rate or determining the type of product produced (). The report, therefore, analyses the effects of the enzyme peroxidase in metabolic reactions and determining its optimum temperature in the reactions.
Materials and methods
Materials used in the experiment included 5-7 g of the potato tissue, 50ml of 2.0M phosphate buffer coffee filter and guaiacol dye.

Methodology
Enzyme peroxidase was extracted from 5-7g of potato tissue by blending it with 50ml of 2.0M phosphate buffer with a pH of 5 then solution filtered through the coffee filter.
The effect of temperature was then determined on the activity of enzyme peroxidase through monitoring its effects under different temperatures of 4, 32 and 600C on the dye guaiacol when it turned brown.
A graph was then plotted to determine the optimum temperature for the enzyme.
Results

Figure1. Graph of slope at temperature

Figure2. Graph of slope at recovery.
Discussion
Temperature increased from 40 C to room temperature of 22.20 C resulting to the increase of the peroxidase activity. This explained that increase in temperature up to the optimum point led to the increase of the breakdown of guaiacol dye to color brown with intensity increasing up to this optimum point. Further increase in temperature to 60C denatured the enzyme and therefore the production of the brown color stopped and its intensity reduced.
From the experiment therefore, the optimum temperature for peroxidase is at 22.20C from graph on figure 1.

The temperature effect is reversible in the case whereby the peroxidase is exposed to temperatures that negatively affect its function. This is through addition of many substrates to the active sites of the enzyme to enhance its activity. From the experiment, it is illustrated from graph in figure 2 with the constant slope from temperature of 40 C to320 C. further increase of temperature to 600C led to the reduction of the activity of the enzyme on the dye as a result of denaturing effect thus less color

intensity.
Conclusion
Increase in temperature increases the rate of enzyme activity to a maximum level. This is because the kinetic energy is increased and therefore more collision of the substrate and the enzyme is enhanced. The rate increases up to the optimum temperature as indicated from the graph of figure 1 at temperature of 22.20 C. This is the maximum temperature at which the enzyme works best. At this temperatures therefore, the metabolic reactions within the body is effectively carried out and thus, any hydrogen peroxide within the cells are broken down to less harmful products (Coppens and Bogaert 34).
Further increase in temperature above this denatures the enzyme and thus the activity and the rate declines. This is illustrated in figure 1 by decline of slope from the temperature of 22.20 C to 600 C. in the graph of figure 2; the slope is from the temperature of 320 C to 600C. These temperatures make it harmful for enzymatic activities in the body because of the denaturation effect and as a result, the hydrogen peroxide accumulates in the cells leading to harmful effects.

Work cited
Daniel, Roy M., and Michael J. Danson. "Review: Temperature And The Catalytic Activity Of Enzymes: A Fresh Understanding."FEBS Letters 587.A century of Michaelis - Menten kinetics (2013): 2738-2743).
Coppens, Noah, and Lucas Bogaert. Peroxidases: Biochemical Characteristics, Functions and Potential Applications. Hauppauge, NY: Nova Science Publishers, Inc., 2013.