Effects of Surface Area on Catalase Activity in Potato.

Authors Avatar

Effects of Surface Area on Catalase Activity in Potato


To investigate the effect of surface area on the activity of Catalase in potato.


I predict that the potato which has been cut into more pieces will have the largest surface area. A larger surface area means that there will be more catalase molecules coming in contact with the reacting substrate, hydrogen peroxide. Enzymes react when particles come into contact with their active sites; if more of the enzyme is exposed (larger surface area) a greater number of active sites will be available to react with the hydrogen peroxide.

The surface area of a 5cm tube with a diameter of 2cm equals 37.0 cms² ( 2  rh+2  r² ), but a 5 cm tube cut into five 1cm segments has a surface area of 62.83 cms². Every time another segment is cut from the 5cm tube two more areas have to taken into account, this means each time the 5cm tube is cut into a piece the surface area will increase. As a larger surface area produces a higher rate of reaction, my results should show a higher volume of gas released when using a potato with a larger surface area.    

Background Knowledge

Enzymes are proteins which can be referred to as biological catalysts. Catalysts are molecules which increase the rate of chemical reactions and remain unchanged at the end of the reaction.

Enzymes are made up of a chain of amino acids which are constructed into a precise three-dimensional shape. The three-dimensional shape of the enzyme is very important as it determines which substrate (the molecule which is broken down by enzyme) the enzyme is compatible with; usually each particular enzyme will only act as a catalyst for one reaction. The 3D shape provides the enzyme with an active site, this is the only place where the substrate can attach itself onto the enzyme and this is also the place where the substrate is broken down to give its product(s). There is usually only one active site on an enzyme sometimes there can be more.

Join now!

(Diagram below explains the active site of an enzyme)

At the end of the reaction the enzyme remains unchanged and the product(s) leave the active site as they no longer posses the active site’s complimentary shape.

Many biological reactions produce hydrogen peroxide; hydrogen peroxide is very harmful to cells. The cells counter the hydrogen peroxide by using an enzyme called Catalase which decomposes the hydrogen peroxide into much safer products,



Catalase possesses an active ...

This is a preview of the whole essay

Here's what a teacher thought of this essay


This is an outstanding introduction to a practical. 1 - The language used is concise and demonstrates a good scientific vocabulary. 2 - The information is well researched and only relevant information has been included. 3 - There are very few errors in structure or language. 4 - The range of the practical needs to be revisited as the interval is not standardized. 5 - Any information that has been included needs to be referenced. ***** (5 stars)