Investigating The Effect Of Macromolecules On The Body : Glucose, Lipids, Starch, And Protein

1438 Words Oct 18th, 2015 6 Pages

The purpose of this lab was to conduct a variety of tests using different indicator methods to classify four different macromolecules in the body: glucose, lipids, starch, and protein. There were four different tests used in to identify which macromolecules were present in each substance. Lipids were identified by the stains they created on a sheet of paper towel. Biuret reagent was added to the substance to identify proteins. Benedict’s Solution (and heat) identified glucose in the substance. Finally, iodine identified the presence of starch in the substance.

The lab took place over the course of two days. The first day consisted of standard experimental tests in order to determine which macromolecules reacted with the indicating reagents. On the second day, the information about each macromolecule obtained by the standardized tests was applied to identify the stomach contents of the victims. The positive tests demonstrated how prominent the macromolecule or combination of macromolecules were in the substance. For lipids, a positive test occurred when a dark, wet looking, translucent stain was present after 30 minutes of drying. The glucose test was positive when the substance turned a bright opaque orange in the presence of Benedict’s solution and heated at 70°Celsius. The positive test for starch occurred when Iodine (Lugol’s) solution turned the substance a deep opaque black/brown/blue colour. Finally, protein was identified in the substance…
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