How the Concentration of the Substrate Affects the Reaction in the Catalase Inside Potato Cells

How the Concentration of the Substrate Affects the Reaction in the Catalase Inside Potato Cells

Introduction

Enzymes are made of proteins and they speed up reactions, this means

that they act as catalysts. Hydrogen peroxide is a byproduct of our

cell's activities and is very toxic. The enzymes in our bodies break

down the hydrogen peroxide at certain temperatures they work best at

body temperature, which is approximately 37 degrees. At high

temperatures, the cells begin to denature. This means that the

hydrogen peroxide is prevented from being broken down because they

will not 'fit' into the enzyme.[IMAGE]

Objective

I am going to find out how the concentration of the substrate,

hydrogen peroxide affects the reaction in the catalase inside the

potato cells. I shall be measuring how much gas is given off. This

will be done by measuring the amount of froth on the surface of the

liquid. The oxygen released is collected in the form of these bubbles.

The equation for the reaction is:

(catalase)

[IMAGE] H2O2 2H2O + O2

(hydrogen peroxide) (2 part water) (oxygen)

I will change the concentration of H2O2 and O2 (making sure the volume

stay the same, when one part of a H2O2 particle is taken, an O2

particle is added.

Prediction

As the levels of H2O2 increase, gas is produced faster and in a

greater quantity. This means that the height of the froth will

increase. The froth is produced due to the gas as it bubbles from the

potato slice. This gas is given off as a waste product from the

reaction where H2O2 (substrate) breaks down the enzymes in the potato.

If I were to roughly plot a graph for the reaction, it would look like

this,

[IMAGE]

The graph shows that as the concentration of hydrogen peroxide is

increased the more oxygen is given off. This is because there is more

hydrogen peroxide to be broken down by the enzyme and with more

hydrogen peroxide in the reaction, more oxygen is released.