Enzyme activity of peroxidase

General Biology I laboratory, BIO 1630 , SPRING 2018

Prof. Louis Sayad

Student. - Liliia Savitska

Enzyme Activity of Peroxidase

TITLE: Analyze effect of temperatures and PH on the activity of enzyme

ABSTRACT: Enzymes are protein that speed up chemical reactions in living organisms. This investigation tested the effects of temperature and pH on enzyme activity. Enzyme used to called peroxidase, it is a large protein containing just over three hundred amino acids. Turnip and horseradish roots are rich sources of this enzyme as are very animal tissues. Catalyze was treated with different temperatures ( 4*C, 25*C, 32*C, 48*C).

Data was collected by measuring the absorbance dose of oxidized guaiacol. The result showed that higher temperatures makes the enzymes more active.

INTRODUCTION

Cells require the use of enzymes to cary on life is functions. These functions include breaking down molecules for energy and building structural molecules such as proteins. Because most reactions require high amounts of energy, they could not occur in a cell without the aid of a catalyst. Enzymes are protein catalysts that bind to molecules allowing them to react faster.

Each enzyme has a very specific purpose. The shape of the active site on the enzymes outer layer determines that purpose, along with deciding substances can bind with that specific enzyme. Most enzymes are proteins with individual shapes determined by they unique amino acids sequences. Any change to the shape of the enzyme can effect its ability to bind to the substance.

HYPHOTESIS

The purpose of this experiment is to measure the effect of the temperature and pH on enzyme function. The enzyme we used is catalase which is common enzyme found in many organism. Catalase breaks down hydrogen peroxide producing oxygen and water.

MATERIAL AND METHODS

For this experiment we used the indicator dye guaiacol, which turns down brown when oxidized. Spectrophotometer where used to measure the oxidation of guaiacol, as the development of a brown color. It gives a possibility to follow the rate of breaking down and cooled to four different temperatures ( 4*C, 25*C, 32*C, 48*C). Absorbance was measured for two minutes with 20 seconds intervals.

RESULTS

As a result we can see that temperatures increases enzyme activity. Temperatures affects the frequency with which enzymes substrate collide and, hence also effects binding. At very high temperatures enzymes functions slow down, because such temperatures break hydrogen bonds that maintain the shape of the enzyme. As the shape of the active site the binding efficiency with the substance is reduced.

Table temperatures effects on peroxidase activity (record absorbance 500 nm)

Time	Tubes 2&3 4*C	Tubes 5&6 25*C	Tubes 6&7 32*C	Tubes 8&9 48*C
20	0.450	0.624	0.752	0.850
40	0.655	0.990	1.102	1.329
60	0.877	1.3311	1.462	1.750
80	1.073	1.647	1.801	2.136
100	1.266	1.952	2.121	2.493
120	1.453	2.247	2.423	2.823

DISCUSSION

The results of the temperatures and pH treatments show a similar pattern. At extreme temperatures 4*C there was very little activity where the most activity where the most activity at 48*C. This indicates that catalase works at or near human body temperatures.

Literatures cited

- Warren D. Dolphin, 10th addition, Biology Investigation. Form, function, diversity & process.