La Cuarterona

Academia María Reina
Biology 11th grade
Mrs. Carla Cabanillas
Name Stephanie Roy Troia Date October 14, 2012
Enzymatic Browning

I. Introduction

In this lab we will be workingwith an experiment with apple slices. We will learn how eat slice will react with a different formula of solutions. Oxidation is the main thing that occurs in the lab with is the interaction betweenoxygen molecules and all the different substances that may contact, from metal to living tissue. This can be destructive, such as rusting and spoiling fresh fruit, which is what occurs in theexperiment with different solutions. When an apple is exposed to air what it contains is enzyme, which is that it reacts with oxygen and iron containing phenols that are found in the apple. The oxidationreaction basically forms a sort of rust in the surface of the fruit, which is what makes it brown when the fruit is cut of damaged because it allows the air to react with the enzyme and other chemicals.II. Materials:
* Apple
* Boiling water
* Lemon juice
* Sugar solution
* 3-250 mL beakers
* Hot plate
* tongs
III. Procedure:
1. Predict the relative amount ofdiscoloration each of these apple wedges will show when exposed to air. Justify your prediction.
Sample 1: Untreated apple wedge
Sample 2: Apple wedge submerged in boiling water.
Sample 3: Applewedge submerged in lemon juice.
Sample 4: Apple wedge submerged in sugar solution.
2. Prepare 75 mL of each of the following: boiling water, lemon juice, and sugar solution in three 250 mLbeakers.
3. Slice an apple into four wedges. Immediately use tongs to submerge each wedge in a different liquid. Put one wedge aside.
4. Submerge the wedges for three minutes, and then place on apaper towel, skin side down. Observe for 10 min., and then record the relative amount of discoloration of each apple wedge.
5. Complete the data table.

IV. Data Table:
Samples | Prediction...