Wednesday, November 6, 2013

Enzyme Catalysis Lab (Part 2D)

Purpose: The purpose of part 2D was to test the cenzyme-catalase. The independent variable tested was time, while the dependent variables was H202 consumed as well as KMno4 used when titrating.

Introduction: Enzymes are proteins that speed up the rate of reactions. In this lab enzymes were used on a substrate. A substrate is a solution whose rate of reaction can be catalysed, or accelerated, by the enzymes. The amount of enzymes and substrate in a solution, along with the amount of time the two are together, determine how much of the substrate is catalysed. In this portion of the lab, time was of the essence when it came to determining the amount of substrate that was decomposed by the enzyme.

Methods: In the experiment we had to determine the rate at which seven different timed trails of 10 mL of 1.5% H2O2 solution decomposed after 1 mL of enzyme-catalase was added. Once the enzyme-catalase was added we started a timer, swirled each solution for the ten seconds, and then let them sit for increasing amounts of time. The amounts of time were 10, 30, 60, 90, 120, 180, and 360 seconds. Once time was up we stopped the reactions by adding 10 mL of H2SO4. We then took 5 mL samples from each trial and titrated each one and recorded the amount of KMnO2 used to titrate the 5 mL samples.     


Graphs and Charts:

Discussion: Both the amount of KMnO4 consumed and the amount of water used started at 2.5 milliliters and ended at the same amount. Between the different cups and the amounts of time for which they were exposed to catalase, the two figures-- KMnO4 consumption and H2O use-- seem to decrease and increase in a wave-like pattern. One will decrease while the other increases proportionately, and at some point they each reach a maximum distance from their starting value and begin to move in the other direction-- one increases while the other decreases. It's normal for the KMnO4 amounts to be opposed in this way to the H2O2 amounts, but under normal circumstances, the H2O2 amounts would not decrease after increasing.

Conclusion: our question was to find out the effiency if the enzyme catalase as time being a variable that is changed. We found out that in the fist few tests that our data supported that the enzyme sped up the reaction. However as time got longer we had varied results with our time and it did not support the claim. Errors that may occur is the measurements of our substances and also the time measured might be a little off. Overall we found that most of our data was somewhat accurate.

References: N/A

1 comment:

  1. Your discussion should have included why the amount of KMNO4 was proportional to the hydrogen peroxide consumed. Also your graph lacked a title and labels for the axis.