Intro
I am going to investigate a factor that affects the rate of enzyme activity
What are enzymes and how do they work?
Enzymes are biological catalysts - catalysts are substances that increase the rate of chemical reactions without being used up. Enzymes are also proteins and thus have a specific shape. They are therefore specific in the reactions that they catalyse - one enzyme will react with molecules of one substrate.
The site of the reaction occurs in an area on the surface of the protein called the active site. Since the active site for all molecules of one enzyme will be made up of the same arrangement of amino acids, it has a highly specific shape.
Generally, there is only one active site on each enzyme molecule and only one type of substrate molecule will fit into it. This specificity leads to the lock and key hypothesis. Source 1: http://www.s-cool.co.uk/a-level/biology/biological-molecules-and-enzymes/revise-it/enzymes
Source 2: http://click4biology.info/c4b/3/chem3.6.htm#one
a) Large globular protein enzyme
b) Active Site where the substrate combines to the enzyme
c) Substrate which fits the active site
d) Activated complex. The substrate is weakened to allow the reaction.
e) Unchanged enzyme/ re-used at low concentration
f) Product of the reaction
In my investigation, I will be using the enzyme catalase, which is found in most living organisms. It catalyses the decomposition of hydrogen peroxide into water and oxygen.
2H2O2 + Catalase > 2H2O + O2
Catalase dramatically reduces the activation energy needed for the reaction. Without catalase the decomposition would take much longer, and would not be fast enough to sustain human life. Hydrogen peroxide is also a dangerous, very potent by-product of metabolism, so it is essential that it is broken down quickly, otherwise it would cause damage to