Quantity of Enzymes and the Rate of Reaction with the Substrate

2466 Words10 Pages
Is there a relationship between the quantity of enzymes and the rate of reaction with the substrate? Hypothesis Using my scientific knowledge my hypothesis is that as the quantity of enzymes increases so will the rate of reaction. Reasons for this hypothesis I am basing my hypothesis on a hypothesis known as the ‘lock and key hypothesis.’ It explains that when an enzyme substrate complex forms by means of a spontaneous reaction the substrate fits into the active site like a key fits a lock. It is known as a spontaneous reaction not because it happens spontaneously but because it requires initial energy in order for the reaction to take place and the products have less energy than the reactants. An active site occurs in the enzyme because a few of the amino acids on the surface of the 3d molecule fold inwards thus creating an indention in the enzyme. The ‘lock and key hypothesis’ uses this analogy due to the fact that only one substrate fits one particular active site. This is because simply the substrate and active site both contain certain elements that will only product certain temporary bonds with particular other elements. However, despite the ‘lock and key hypothesis’ theory being very strong it was discovered that there was a flaw in the theory. It was realised that small molecules like water could enter the active site. This caused for a refinement in the theory to be made. The refinement was the cause of the discovery that when a substrate enters an active site small changes in the active site have to occur before the spontaneous reaction can take place. This background information is what I am using as a foundation for my hypothesis. This is because as I increase the surface area I will be exposing more enzymes, therefore more active sites are made available for the substrates to be pulled towards them. I will be able to see the rate of reaction increasing because as I increase the surface area more oxygen will be released due to the catalytic reaction. However, if I was looking at increasing the concentration of the substrate rather than the quantity of enzymes I would find that there would be a limit to the amount in which the rate of reaction could increase. Therefore on the graph after a certain amount of positive correlation the line would stay at the same level.
Open Document