How to measure the rate of a chemical reaction catalysed by an enzyme and then how I can change the rate at which the enzyme speeds up the chemical reaction.

Authors Avatar

Biology coursework: GCSE

I am going to investigate how to measure the rate of a chemical reaction catalysed by an enzyme and then how I can change the rate at which the enzyme speeds up the chemical reaction. The reaction I am going to investigate is

Hydrogen Peroxide   Water + Oxygen

         2H20                 2H20   +     02

Catalyse is an enzyme found in all living cells. It causes Hydrogen peroxide to decompose into water (H20) and oxygen (02).

Enzymes are able to increase the rate of a chemical reaction without being used up in the process. Enzymes are very efficient and small amounts at low temperatures can produce results that would usually require high temperatures and violent reactions. Increases in temperature can speed up the reaction; however enzymes become unstable when heated.

Different factors that affect the speed of a chemical reaction that is catalysed by an enzyme are:

Temperature

When the temperature is increased the particles move faster as they have more energy. This results in more collisions, and the particles collide with higher energy, therefore the reaction is quicker. Heat can sometimes cause an enzyme to become out of shape, causing the substrate to no longer fit into the active site.

Concentration

If the solution is more concentrated it means there are more particles of reactant between water molecules. This makes collisions between important particles more likely to happen. In gas, increasing the pressure means the molecules are more compressed, so there will be more collisions.

Surface area

If a reactant is a solid it will have a relatively small surface area.  Breaking it down into small pieces will increase the surface area, so more of the surface is exposed in the solution. There is more area to work on, and more useful collisions will happen.

The factor I have chosen to investigate that will affect the rate at which the enzyme changes the rate of the reaction is concentration.

Prediction

When I change the concentration it will affect the speed of the enzyme reaction.

I predict that the stronger the concentration of the substrate, the faster the speed of the reaction will be.

Join now!

The enzyme works as a catalyst. This works by giving the reacting particles a surface area to stick to, where they can bump into each other. This increases the number of successful collisions, and therefore the speed of the chemical reaction is increased.

Molecules are constantly moving around and bumping into each other. When a substrate molecule, in this case hydrogen peroxide, bumps into a molecule of the right enzyme it fits into a depression called the active site on the surface of the enzyme molecule. The reaction then takes place and the molecules leave the enzyme, freeing it ...

This is a preview of the whole essay