Peroxidase Lab Report

Gaining Knowledge of Enzymes
INTRODUCTION

The definition of an enzyme is a type of protein that induces reactions. Many enzymes have their own shape that is there because of a certain amino acid(“Biology” 79). Each enzyme has a small part called the active site. The active site is what makes up the enzymes abilities. The active site decides whether an enzyme can bond with a specific type of molecule,and this is known as the substrate of the enzyme. An enzyme substrate complex forms when there are weak, noncovalent chemical bonds, and the the substrate and enzyme intertwine. The ability for the substrate to bind is reduced when the shape of the active site is changed.
The enzyme that we gathered data on is known as peroxidase. Peroxidase is an iron ion that has over three-hundred amino acids. It is also very good for an experiment because of its easy preparation(“Biology” 80). In the lab we had to figure out what the effects of different factors on peroxidase. The procedure on peroxidase could be generalized to all enzymes.

METHODS

Setting up the lab began with labeling four, fifty ml breakers as

follows:peroxidase; buffer, pH 5; 10 mM H2O2(substrate); and 25 mM guaiacol(dye). Then, label four pipettes to go along with the beakers. Then, number seven test tubes as follows:
1.All reactants but no enzyme; to be used as a blank in calibrating the spectrophotometer
2.Substrate and dye
3.Dilute concentration of peroxidase
4.Substrate and dye
5.Medium concentration of peroxidase
6.Substrate and dye
7.Concentrated peroxidase(“Biology” 80)

After this, we set our spectrophometer to zero absorbance at 470 nm using test tube 1.

Having two people in the group, we had one person be a timer and a spectrophometer reader, and the other was the data recorder. After recording the time, we then mixed tubes 2 and 3. We then recorded the data of the combined tube and wrote down the results. After this, we mixed tubes 4 and 5 and completed the same procedure as with tubes 2 and 3 (“Biology” 80). We then had to determine the effect of temperature. We found the results of these four temperatures:
1.In a refrigerator at 4 degrees C or an ice bath at around 0 degrees C
2.At room temperature (about 23 degrees C, but should be

measured)