Enzymatic Actvity

INTRODUCTION.

        Catalysts are substances that speed up a chemical reaction without undergoing any permanent chemical changes to itself. Enzymes are proteins that act as biological catalysts in a biochemical reaction by lowering the activation energy needed which is to allow more collision between substrate thus increasing the rate of product formed. Enzymes are also known to regulate the rate of chemical reaction. However, their structure and function can be altered by various factors and could directly affect the enzyme activity. The experiment was carried out to manipulate these factors that affect enzyme activity. The enzyme that was used is catalase, which was in form of avian blood to react with toxic compound hydrogen peroxide, H2O2 and produces oxygen and water. Below is the chemical equation of the reaction:

2H2O2 + catalase = 2H2O + O2

        From the equation, it is known that a high rate of reaction produces a high directly influence a high amount of oxygen produced. Thus, measuring amount of oxygen produced gives a measurement on the rate of enzyme activity in the reaction. The factors that were accounted for are substrate concentration, temperature and pH level.  

OBJECTIVES.

In this experiment, the objectives that should be achieved are:

1. Able to explain how enzymes function as biological catalysts
2. Explain how environmental factors such as temperature, pH, and substrate concentration affect enzyme activity.

APPARATUS AND MATERIALS.

PROCEDURE.

Part A: Enzyme Activity as a Function of Substrate Concentration

      [pic 1][pic 2]

           [pic 3]

Part B: Enzyme Activity as a Function of Temperature

[pic 4]

Part C: Enzyme Activity as a Function of pH

[pic 5]

RESULT.

Part A: Enzyme activity as a function of substrate concentration

[pic 6][pic 7][pic 8]

Part B: Enzyme activity as a function of temperature

[pic 9][pic 10][pic 11]

Part C: Enzyme activity as a function of pH

[pic 12][pic 13][pic 14]

DISCUSSION.

        Catalyst is a chemical that increases the rate of chemical reaction. Enzymes are proteins functioning as catalysts that speed up reaction by lowering the activation energy. Enzymes are highly selective catalysts, meaning that enzyme only speeds up a specific reaction.

For part A, the aim of this activity is to determine the effect of enzyme’s concentration to the rate of reaction. In theory, the rate of reaction will increase when the concentration of enzyme is increase but remain constant after a certain value. This is due to the limiting factor. In this case, the limiting factor is the concentration of substrate which is avian liver in this experiment. A rectangular hyperbola curve graph should be obtained. Based on this experiment, the results approves the theory. The concentration of hydrogen peroxide, H2O2 is controlled using number of drops of the solution. The maximum height of bubble, which represents the rate of reaction, increases in accordance to the concentration of H2O2 but remain constant starting from 9 drops. This is because the rate of reaction is limited by the concentration of the avian liver. A rectangular hyperbola curve graph is obtained.

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