To investigate the effect of surface area on the rate of reaction using the enzyme Catalase, found in potato, and the substrate Hydrogen Peroxide.

Essay by StephatLondonA+, February 2004

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Enzymes are biological catalysts that speed up chemical reactions, without being used up or changed. Catalase is a globular protein molecule that is found in all living cells. A globular protein is a protein with its molecules curled up into a 'ball' shape. All enzymes have an active site. This is where another molecule(s) can bind with the enzyme. This molecule is known as the substrate. When the substrate binds with the enzyme, a product is produced. Enzymes are specific to their substrate, because the shape of their active site will only fit the shape of their substrate. It is said that the substrate is complimentary to their substrate.

When the substrate binds with the enzyme, it forms an enzyme-substrate complex. The reaction happens immediately after and the substrate is broken down in to either two or more products causing a catabolic reaction. Or two or more substrates are bonded to make one product causing an anabolic reaction.

There are five factors that effect enzyme activity. They are:




·Substrate Concentration

·Enzyme Concentration

The factor I am changing is surface area of potato containing Catalase. By increasing the surface area of the potato, you make more Catalase molecules be exposed to hydrogen peroxide. This will result in the rate of reaction increasing because it increases the chance of more successful collisions between the enzyme and the substrate.

Catalase is an enzyme found in food such as, potato. It is used to break down a poisonous by-product of metabolism called hydrogen peroxide. Hydrogen peroxide is a compound that can kill cells therefore; it is essential that our body can break it up. Catalase breaks down hydrogen peroxide into oxygen and water.

Below is the reaction equation for the decomposition of hydrogen peroxide.



To increase the surface...