|
|
This is only a preview of the paper
Click here to register and get the full text.
Existing members click here to login
|
|
|
... An enzyme is a protein that speeds up one or more biological reactions. In biological systems, reactions may occur very slowly, or not at all, in the absence of an enzyme. Enzymes will greatly increase the rate of formation of the product. Enzymes can increase the rate of reactions by a factor of at least a million.
Introduction
Hypothesis
The hypothesis that I am going to test during this investigation is:
Increasing the temperature increases the rate of an enzyme controlled reaction. ... An enzyme is a protein that speeds up one or more biological reactions. In biological systems, reactions may occur very slowly, or not at all, in the absence of an enzyme. Enzymes will greatly increase the rate of formation of the product. Enzymes can increase the rate of reactions by a factor of at least a million. ... This means that each enzyme will normally only catalyse one reaction. The substance that the enzyme combines with is called the substrate, which combines with the enzyme at a particular place on the enzyme’s surface called the active site.
Enzyme molecules are usually much larger than their substrates, with the active site forming only a small part of the enzyme. The rest of the enzyme’s structure is involved in maintaining the shape of the active site. ... Enzymes increase the rate of reactions by reducing the free energy of activation, so that the barrier to a reaction occurring is lower in the presence of an enzyme. The combination of enzyme and substrate produces a new energy profile for the reaction, with a lower activation energy. ... They are also affected by temperature, as a temperature over about 40oC will break the bonds that hold together the active site, so the enzyme molecule will no longer fit the substrate molecule. The Q10 law states that for every 10oC rise in temperature, the rate of reaction will double, up to about 40oC.
Key variables
To test out my hypothesis I am going to look at how temperature affects the catalysis by amylase of the breaking down of starch. In this experiment the changing variable is temperature. All of the other variables- enzyme and substrate concentration and the volume of reactants used will remain the same.
Predictions
In this experiment, I predict that as the temperature increases, so the rate of reaction will increase. However, once the temperature passes 40oC, the rate will fall rapidly, as the enzyme is denatured by the heat.
Approximate Word count = 1991
Approximate Pages = 8
(250 words per page double spaced)
|
|
|
|
|
|