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 I. Effect of Substrate

 I. Effect of Substrate Level

For 1 ml of Catalase A, we took measurements every 30 seconds of the amount of gas being produced in cm.

Results: .25, .75, 1.5, 2.4, 3.4, 4.75, 5.5, 5.75, 6, 6.5, 6.5, 6.5

These results show that the enzyme was effective for a certain amount of time before the levels plateaued, and the class results show that if less substrate is used, it does not produce as much gas and plateaus sooner.

II. Effect of Enzyme Concentration

For each concentration of catalase, we timed how long it took for a filter soaked in each type of catalase to rise to the top of a beaker filled with hydrogen peroxide. 

Catalase B: 5 sec, 4 sec, 5 sec

Catalase C: 27 sec, 16 sec, 16 sec

Catalase D: 62 sec, 135 sec, 105 sec

As the concentration of the enzyme decreased, the time it took to float increased. This, along with our classmates results, leads us to believe that more enzymes leads to faster reactions. 

Other results include a U-shaped graph for both temperature and pH levels.

To explain the phenomena of how the enzyme itself is not destroyed in the reaction, we predict that the enzyme is not actually a part of the reaction itself, but instead affects the substrate involved in the reaction in order to increase the speed. (It acts as a catalyst.) This may be done through changing the activation energy needed for the reaction to occur, or by changing the shape or destabilizing the substrate in some way that makes it more likely to break down. Enzymes must be material-specific because they do not seem to be corrosive to all substances. Also, if our theory is correct, every reaction has a different activation energy necessary for it to occur. In terms of temperature and pH, there seems to be a very specific range for this enzyme to function. This indicates that it may be an organic substance, such as a protein. This means that at a certain pH or temperature, qualities of the enzyme (ex. shape) may alter to the point that it is no longer effective. 


David Richardson and Julia Stuart


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