Prediction: I predict that as the temperature increases, the rate of reaction will increase. After the optimum temperature 40C the rate of reaction will rapidly decrease.
I found out that temperature did have an effect on enzyme catalase. This can be shown by these graphs:
Results Table: Results for affect of temperature on enzyme catalase investigation
This table shows the number of bubbles produced (O2) in the space of 5 minutes. When investigating the effect of different temperature on the enzyme catalase. To find the average rate of reaction I added the total of reaction rates and divided them by three.
Graph of results
Analysis and conclusion
After plotting my results on the graph, I have found that as you increase the temperature the rate of reaction increases
This relationship happens up to a certain point. Above a temperature of 40°C, the rate of reaction rapidly decreases and only a very little amount of O2 was produced at 50C or 60°C. This probably had nothing to do with the enzyme. It is likely, as it is such a small amount, that the O2 produced was the natural breaking up of hydrogen peroxide. At 100C there was no rate of reaction.
This relationship agrees with my prediction that the rate of reaction would reach its peak around the optimum temperature (40C), above the optimum temperature the rate of reaction would decrease
The relationships correspond with the Enzyme theory. At low temperatures the enzyme molecules have very little energy, this results in few collisions between the enzymes and substrates and thus few reactions. Enzymes are therefore still active at low temperatures, they do not collide enough to cause lots of reactions. When the optimum temperature is reached the enzymes work at there full capacity. This means at all times the enzyme is mediating reactions due to continuous collisions.
Above the optimum temperature the collisions become increasingly violent. The enzymes 3D shape denatures due to the collision and temperature breaking the bonds. Therefore number of reactions decrease.
At a high temperature the enzyme will be completely denatured due to the complete collapse in its 3D structure.
In relation to the human body this experiment illustrates one of the primary functions for the enzyme catalise to work efficiently. The optium temperature for enzymes catalase to work efficently is 37C. all chemical reactions need enzymes. They speed up (catalase) reactions that otherwise take too long to allow humans to survive. So the body need to be at the optium temperature for the enzymes to calalise the substrate eg. carbohydrate and protiens (potato). Above the optimum tempertaure, the rate will rapidly decrease and cause the enzyme molecules to permantly change shape, destroying their active sites (i.e denatures the protien). This change is irrversable.
Background science
At a high temperature the enzyme will be completely denatured due to the complete collapse in its 3D structure.
Catalase is an enzyme found in all living cells. It makes Hydrogen Peroxide decompose into water and oxygen.
You can represent this in the equation:
2H2O2 =2H2O + O2
Enzymes: Enzymes are able to increase the rate of reaction without actually being consumed in the process. In all, enzymes are very efficient. Small quantities at low temperatures are able to produce results, which would require high temperatures and a violent reaction from any normal chemical means. Although increases in temperature may speed up the reaction, enzymes are unstable when heated.
Evaluation
The experiment went well, this is because I had an accurate set of results, which corresponds with my predictions. Also there were no abnormal patterns that occurred because my experiment was carried out fairly and accurately. I feel that if I had repeated the experiment more times my evidence would have been more tangible to support in of the enzyme theory.
