Investigation into the effect of substrate concentration on the activity of the enzyme catalase.
Investigation into the effect of substrate concentration on the activity of the enzyme catalase
2H2O2 → 2H2O + O2
Hydrogen Peroxide → Water + Oxygen
The aim of this experiment is to investigate the affect of different concentrations of substrates on the rate of activity of the enzyme catalase.
I will achieve this by diluting 10 volume hydrogen peroxide ten times to acquire 10 consecutively more dilute solutions. These will then be added to the same concentration of yeast suspension. The experiments will be performed at room temperature and oxygen will be collecting via a water bath and measuring cylinder.
My predication is that as I increase the concentration of the substrate (hydrogen peroxide), the speed in which the reaction takes place, and amount of products produced will increase. This is because of the following reasons. Firstly, at a lower concentration of substrate, the amount of enzyme molecules present in the yeast would greatly outnumber the molecules of substrate being added. This means that not all the active sites are in use resulting in a slow reaction rate, as collisions between the active site and the substrate molecules would be less frequent. Also, less gas would be evolved due to the small amounts of substrate with which the enzyme would react. However, if the concentration of the substrate were increased, due to the increased number of substrate molecules in the solution, collisions would be more frequent. This would mean an increased rate of reaction, as more of the enzyme molecules would be in use. A rise in gas evolved may also be apparent. Conversely, there is also a point in which an increase of concentration would have no effect on the rate of reaction. This is because all of the enzyme molecules are in use, and substrate molecules are ‘effectively queuing up’. The maximum working rate of the enzyme is known as Vmax.
