Enzymes Internal Assesment Essay

1622 WordsFeb 3, 20147 Pages
IB Internal Assessment: The Effect of pH on Polyphenoloxidase Enzyme Activity Research Question: What is the effect of different pH levels on the polyphenoloxidase enzyme activity? Background Information: The polyphenoloxidase enzyme is found in lychee and plenty of other produce as well. Measuring the absorbance rate of it in different pH levels aids in evaluating at which pH level does the enzyme work best. In other words, each enzyme has its own optimal pH at which it works its best in speeding up the reaction. Leading to the hypothesis, if the pH level is at 7.0, then the polyphenoloxidase enzyme will work better than if it was working at any other level of pH. Variables: | Units | Range | Independent Variable | pH Level | | | Dependent Variable | Absorption Rate | | | Independent Variable Levels | pH Levels | 1 | 4 | *7 | 9 | 13 | Trials | 5 | 5 | 5 | 5 | 5 | *Also indicates control Controlled Variable | Units | Method of Controlling | Reason for Controlling | Lychee | - | The same lychee was used | Different lychee’s could have different amounts of pigment in them, thus affecting the experiment | LoggerPro and the Colorimeter | - | The same exact software was used | Usage in different a software might skew the numerical data | Distilled Water | mL | Distilled water was used throughout the entire experiment | Distilled water is almost everywhere, so it is better to use when experimenting to get reliable results | Materials: Item | Quantity | Vernier LoggerPro Software | 1 | Colorimeter | 1 | Computer | 1 | Blender | 1 | Graduated Cylinder | 200 mL | Lychee | 10 grams | knife | 1 | 50 mL beaker | 5 | 200 mL beaker | 1 | Distilled water | 250 mL | HCl | 50 mL | Vinegar | 50 mL | Bleach | 50 mL | NaOH | 50 mL | pH Strips | - | Paper towel roll | 1 | Guaiacol | - | Cuvettes | 6 |

More about Enzymes Internal Assesment Essay

Open Document