There are few vegetables and fruits that turns to the color brown if their surface is exposed to oxygen. Once the veggies or fruits been exposed to oxygen, then the browning begins to appear, and electrons and hydrogen will be removed. This happens because of an enzyme called catechol oxidase. The enzyme will act on its substrate catechol to form a yellow compound which then reacts with the oxygen in the air and change into benzoquinone. The more concentration of the enzyme, the more browning appears. Catechol oxidase is found in cell cytoplasm, their function in plants are to "help protect damaged plants bacterial and fungal disease." The objective of this experiment is to test the presences of catechol oxidase in various fruits and vegetables. Our group hypothesis states that, If catechol oxidase is present in the selected extracts, the null hypothesis is that catechol oxidase is not present in the selected extracts. Next, the prediction would be, if catechol oxidase doesn't differ with other enzyme sources, then the rates will …show more content…
Fill each cuvettes with its respective solution. Turn on the spectrophotometer, so it can warm up then calibrate it to 0% absorbance. Put the corresponding extract blank and set the spectrophotometer to 100% transmittance, then calibrate it to 540 nm. Once catechol is added in the cuvettes, make sure the solution is mixed. Place carrot cuvette in the spectrophotometer and record the resulting transmittance. Record the amount of absorbance by converting transmittance every 5 minutes for a total of 20 minutes. Repeat all of these steps for the cantaloupe, banana, replacing the blank each time to recalibrate the spectrophotometer. After recording all the percent transmittance value, the data was then converted into absorbance value by using the absorbance conversion table. The information was placed on a plotted graph