Starting from Scratch with Life's Macromolecules
24 September 2013
The purpose of this lab was to use the standard test, developed by biochemist, to determine the presence of the most abundant macromolecules in a number of products. Those macromolecules included carbohydrates, lipids, and proteins. In this experiment there were four indicators, three of which were Benedict's solution, Iodine solution, and Biuret reagent as shown in figure 1. Those three indicators are liquids, the change in color indicated when it reacted with a specific substance when dropped into a certain substance. However the last indicator was paper towel, and the way of determining if the substance reacted was through the amount of residue left after drying out. Each product was tested with each indicator. If certain indicators are added to certain products they'll be a color change in the solutions indicating which group of macromolecules it belongs to. Glucose and fructose will test positive during the buiret reagent test for a sugar, therefore a carbohydrate. Starch will test positive for a starch when mixed with iodine, therefore a carbohydrate. Egg whites will test positive when mixed with the biuret test for a protein, and vegetable oil will test positive when placed on the paper towel for a lipid. This is because, through research it shows, what should happen when each indicator is place in a certain macromolecule.
A carbohydrate stores energy, contains carbon, hydrogen and oxygen and has three types which are, monosaccharides, disaccharides, and polysaccharides. Monosaccharides have three to seven carbon atoms, a disaccharide has two monosaccharides and a polysaccharides has many. Three types of carbohydrates that where used during this experiment were glucose (monosaccharides), fructose (monosaccharides), and starch (polysaccharide). We used two ways to test for the presence of carbohydrates. For testing...