Enzymes

LAB #6:

ENZYMES

INTRODUCTION

What is an enzyme? Enzymes are composed of mostly proteins but may be made up of non- protein cofactors, which are vitamins or metallic ions. In reactions, enzymes are used at catalysts. Catalysts are used to accelerate particular reactions by lowering the activation energy. An enzyme can lower the activation energy when reactants bind to a specific part of the protein called the active site. An active site changes the shape of the enzyme and fits precisely with the reactant. In a reaction, there are substrates and reactants that make a product. Various factors influence the effectiveness of an enzyme. Two factors are the pH concentration and the temperature. Also, the factor temperature can affect the enzyme in two ways. The first way is by affecting the shape of the protein. The second way is by increasing the energy level of the substrates. As a result, because enzymes must bind to substrates to catalyze the reaction, and each reaction requires a certain amount of time, the enzyme concentration also influences the reaction rate.

PURPOSE

The purpose of today's lab is for you to investigate the kinetics (rate of reaction) of an enzyme-mediated reaction and to determine how various factors influence those kinetics.

PROCEDURE

To start off with, be sure to accurately dispense the precise amount of each substance using the pipettes provided. Also, do not cross-contaminate the reagents or you with be severely chastised. The first step is to turn on the spectrophotometer. Set the wavelength at 500nm. Set the limits so that the % T scale reads from 0% to 100%.

A.) The first step is to experiment with the enzyme extract and determine if it needs to be diluted. Next, set up test tube A with 2 drops of guaiacol and mix with 2 ml of hydrogen peroxide. Then, in test tube B, mix 1ml of enzyme extract and 3ml of tap water. Carefully and quickly, pour the two test tubes into a clean cuvette. After, place the cuvette into the...