Research question: What is the effect of adding lead nitrate solution on the activity of amylase enzyme?
Aim: To test the effect of adding nitrate solution on the activity of amylase.
Background Information:
Inhibitors are molecules which repress or prevent another molecule from engaging in a reaction. They are substances that attach themselves onto an enzyme and reduce or prevent the enzyme’s ability to catalyse reactions. Competitive Inhibitors are inhibitors that occupy the active site of an enzyme or the binding Site of a receptor and prevent the normal substrate or ligand from binding. An active site is a region on the surface of an enzyme to which substrates bind and which catalyzes a chemical reaction involving the substrates. Thus the inhibitors prevent the enzyme activity when the concentration of the substrates is very low. As the substrate concentration increases so does the enzyme activity. Non-competitive inhibition is an Enzyme inhibition in which the inhibiting compound does not compete with the natural substrate for the active site on the enzyme but inhibits reaction by combining with the enzyme-substrate complex after the complex is formed. An example of a non-competitive inhibitor is ATP. When ATP accumulates it binds to a site other than the active site on the enzyme phosphofructokinase. In doing so it changes the enzyme conformation and lowers the rate of reaction so that less ATP is produced.
Hypothesis: There is an inverse relationship between the mass of lead nitrate and the ability of amylase to convert starch into maltose.
Variables:
Independent Variable:
The mass of lead nitrate dissolved in each of the solutions.
Dependent Variable:
The change in the color intensity of the iodine.
Controlled variable:
Time: the reaction was allowed to proceed for twenty minutes.
Temperature: the water bath was set at 40˚C. This was to provide the optimum conditions for the enzyme activity.