Macromolecules In Cells Lab Report

Discussion The lab allowed the experimenters to learn more about the macromolecules in cells. We tested for the presence of proteins, sugars, fats, and starches in solutions. The question for this lab is “How does an experimenter detect the presence of certain macromolecules in a substance?” We found the answers throughout the lab. Our hypotheses for the biuret reagent test is the the distilled water will turn blue, showing a negative test result. Also, the albumin will turn purple, showing a positive test result. For the iodine test, our hypothesis is that the water will turn orange and the starch suspension and potato juice will be black. In other words, the distilled water tube will have a negative result and the starch suspension and potato juice will have a positive result. The hypothesis for the benedict’s reagent test is the test tube containing water will be blue after heating and the test tube containing the glucose solution will be orange after heating. This means that the water test tube will have a negative result and the glucose solution will have a positive result. Lastly, our hypothesis for the lipid test is that the water would sit on top of the brown paper and the oil will eventually soak into the paper.

To test the presence of proteins, one must perform a biuret test. The biuret reagent changes the colors; blue meaning no protein and purple meaning there is a protein. For the presence of starches, one has to perform an iodine test. As before, the iodine changes colors; orange meaning no starch and black meaning a starch is present. The presence of sugars are tested by a benedict’s reagent test is performed. The color blue means no sugar is present, yellow mean some sugar is present, and orange means a high amount of sugar is present. The test for lipids is quite simple, just drop a droplet of the solution on a piece of brown paper. If the solution is a lipid, it will leave an oily