Materials and methods for macromolecule unit analysis

Mat Meth

Materials & Methods

Further Elucidation of Lipids and Their Chemical Properties

A test tube was labeled "L+" and filled halfway with water. Ten drops of vegetable oil were added to the tube. A test tube labeled "L-" was similarly filled halfway with water, and ten additional drops of water were added. Both test tubes were shaken so as to thoroughly mix the contents, and five drops of Sudan IV solution were added to each tube. Both tubes were then placed in a test tube rack to rest for five minutes before each was removed and again shaken to mix the contents. After this second mixing, a dropper full of detergent water was added to the test tube labeled "L+" and shaken vigorously to mix this emulsifier into the solution. The contents of the tube were carefully observed with the naked eye and results recorded.

: Identification of Macromolecules in Everyday Items

A test tube was labeled "RS+" and two ml of glucose solution were added to the tube, while a test tube labeled "RS-" received two ml of water. Two ml of Benedict's reagent were then added to each tube and the tubes were gently shaken to mix the solution. A beaker of water was set to heat on a hotplate at 100 degrees Celsius, and after shaking the two test tubes were placed in this beaker of water, still on the hotplate, for three minutes before being removed and placed in test tube racks. Two ml of starch solution were added to a test tube labeled "S+," and two ml of water were added to a test tube labeled "S-." A dropper full of iodine was added to each test tube; tubes were then gently shaken and placed in a test tube rack. Two final test tubes were labeled "P+" and "P-," with the "P+" tube receiving two ml of egg albumin and the "P-" tube receiving two ml of water. Two ml of Biuret reagent were added to each tube, and the tubes were then gently shaken, rested for two minutes, and placed in a rack. Visual observations were recorded.

4.4 Identification of Macromolecules in Household Substances

Nine test tubes were labeled in sets of three: "B1," "B2," "B3"; "S1," "S2," "S3"; and "L1," "L2," "L3." Two ml of baby formula solution was added to ach of the "B" tubes, tow ml of sports drink solution to each of the "S" tubes, and two ml of lemon-lime soda solution to each of the "L" tubes. The procedures used for the positive tubes (those labeled with a "+") in the experiment above, section 4.3, were then applied to these tubes -- tubes "B1" "S1" and "L1" all received two ml of Benedict's reagent, were heated at 100 degrees Celsius for three minutes and placed in test tube racks; tubes "B2" "S2" and "L2" all received a dropper full of iodine and were gently shaken before being placed in the test tube rack; and tubes "B3" "S3" and "L3" all received two ml of Biuret reagent before being gently shaken, rested for two minutes, and then placed in the test tube rack. Observation was again made with the naked eye and recorded.