Before you begin the scientific investigation below, make sure to download the Enzymatic Browning Scientific Investigation Report. As you complete this scientific investigation, fill in any needed information on the report template. If you need more information about each section of the report, please visit the Developmental Module.
This scientific investigation is available below or in a printable version.
Introduction
Have you ever reached into a fruit bowl and grabbed a piece of fruit, only to notice that it is soft and brown? Or have you sliced a raw potato for French fries, but let them sit while you did something else only to come back to brown, unappetizing food? The brown color is the result of a chemical reaction involving enzymes called oxidation. This reaction occurs when a group of enzymes called polyphenol oxidases in the plant cells are exposed to oxygen.
Objectives
In this scientific investigation, you will:
Hypothesis
Using the Procedure and Data Collection section below, read through the procedural information for this scientific investigation. Based on your understanding of the procedure, develop your own hypotheses which describe your expected results. You should consider the following questions: Which treatment, if any will slow the oxidation reaction? What are the practical applications of this information? Record your hypotheses in the Hypothesis section of your Enzymatic Browning Scientific Investigation Report.
Equipment and Materials
Procedure and Data Collection
(area browned / total area of square) x 100 = percentage of pear that has browned
Data
Use the table provided in the Data section of your Enzymatic Browning Scientific Investigation Report to record your data from this scientific investigation. The data table is also shown below:
Liquid or Solution | Measurement | Time Increment | ||
10 Minutes | 20 Minutes | 30 Minutes | ||
Boiling Water | Brown Area (cm2) | |||
Percentage of Pear That Has Browned | ||||
Sugar Solution | Brown Area (cm2) | |||
Percentage of Pear That Has Browned | ||||
Salt Solution | Brown Area (cm2) | |||
Percentage of Pear That Has Browned | ||||
Lemon Juice | Brown Area (cm2) | |||
Percentage of Pear That Has Browned | ||||
White Vinegar | Brown Area (cm2) | |||
Percentage of Pear That Has Browned | ||||
None | Brown Area (cm2) | |||
Percentage of Pear That Has Browned |
As part of your data collection, create a line graph that shows the percentage of pear that has browned at each time increment for each of the different solutions. Each solution should be represented by a different colored line, and the graph should include a key. In addition, make sure to include labels and a title for your graph.
Data Analysis
In the Data Analysis section of your Enzymatic Browning Scientific Investigation Report, provide responses to the following questions. Make sure to completely answer each question.
Conclusion
Using the Conclusion section of your Enzymatic Browning Scientific Investigation Report, compose three to four sentences describing an overall conclusion based on your data. Was your hypothesis supported or not, and how do you know? Use the data and notes that you collected from you experience to form you conclusion. Make sure that you include information that you gained from data analysis to support your conclusion.
Experimental Sources of Error
On your Enzymatic Browning Scientific Investigation Report, provide responses to the following questions: Are there any sources of error? If so, what are they, and what could be done to minimize error?
Once you have completed the Enzymatic Browning Scientific Investigation Report, please submit your work to the dropbox.