Temperature Effects in Enzyme Activity

Temperature Affecting Enzyme Activity

Introduction

The basic properties of life revolve around chemical reactions. Without the presence of enzymes some of life's processes would not come so easily. Enzymes are basically proteins, which have specific shapes for different substrates. Enzymes change the rate in chemical reactions. It does this without having to change its own shape, which makes enzymes different from other proteins. A common enzyme that we have is catalase, which breaks down hydrogen peroxide into the products water and oxygen.

To observe this catalase activity I used small amounts of liver samples slightly smaller than the size of a pea to see the reaction when hydrogen peroxide is added to it. In this experiment I exposed the liver samples in three different temperature environments: 3oc, 22oc, and 75oc. I wanted to measure how much water and oxygen is produced in each environment by measuring the visible bubbles in each test tube. I predicted that water and oxygen production would occur less in the colder temperature, and none would be produced in the higher temperature.

Materials and Methods

3 test tubes were set up to accommodate each of the three liver samples.

Each test tube containing the liver samples was exposed to different temperature environments before the addition of hydrogen peroxide. The tested environments were performed in room temperature, near boiling water, and nearly freezing.

Test Tube 1: 2 ml of hydrogen peroxide added to liver at 22o degrees Celsius.

Test Tube 2: 2 ml of hydrogen peroxide added to liver at 75o degrees Celsius.

Test Tube 3: 2 ml of hydrogen peroxide added to liver at 3o degrees Celsius.

Test tube 3 was kept in ice to regulate the cool temperature during the experiment. Test tube 2 was taken out of nearly boiling water to add the hydrogen peroxide for safety. Test tube 1 was kept out in room temperature during the experiment. Measurements of the bubbles inside the test tubes were recorded every minute for about 10 minutes in centimeters (Dept. of Life Sciences, 2006).

Results

The water and oxygen production slowly decreased over the 10 minutes among all samples (Table 1). The amount generated most appeared to be in room temperature and followed by the cooler temperature sample. The heated liver sample was minimal in the chemical reaction and was barely measurable.

Table 1

Room Temp 3oC 75oC

Minutes Bubbles in (cm) Bubbles in (cm) Bubbles in (cm)

0 8.5 6 .3

1 8.3 .3 .2

2 8.0 .25 .1

3 7.8 .2 .1

4 7.6 .2 .07

5 7.5 .2 .05

6 7.5 .2 .03

7 7.4 .2 .025

8 7.4 .2 .011

9 7.3 .2 .011

10 7.3 .2 .011

Comparison