Organic compounds found in organisms include: carbohydrates, proteins, lipids, and nucleic acids. Each play an integral part in biological systems, for instance, carbohydrates are the main source of fuel for organisms. Proteins contribute to the structure of organisms, lipids make up membranes of cells, and nucleic acids make up DNA and RNA for carrying the genetic code. Scientists have established different ways to indicate presence of these compounds, one way is to test for these various compounds via solution tests.
Scientists have established terms for evaluation. The terms include positive and negative control. Positive control contains the variable for which the test will react positively. A negative control on the other hand does not contain the variable and thus will result in a negative result. Solutions which contain the variable or compounds which react with the tests will produce a positive control; otherwise a negative control will result. Materials and Methods An experiment was carried out to test the presence of certain organic compounds found in various solutions.
The Benedict’s test is to test for reducing sugars, Iodine test tests for starch, Biuret test tests for proteins, specifically peptide bonds between amino acids, lastly Sudan IV tests for lipids. Ten drops of various solutions including: onion juice, potato juice, sucrose solution, glucose solution, distilled water, reducing-sugar solution, and starch solution where each tested by Benedicts and Iodine tests respectively. For the Benedicts test, each test tube containing the solution and 2mL of Benedict’s solution were each placed in a hot water-bath for three minutes then examined for color change.
The Iodine test was not however placed in the water-bath. For the Biuret test, solutions that were tested for include 2mL of each: egg albumin, honey, amino acid solution, distilled water, and protein solution. The Sudan IV test was carried out for the following 1mL solutions: oil with water, oil, honey, distilled water, and a known lipid solution. Lastly an experiment for polarity was also conducted which consisted of oil mixed with distilled water and acetone respectively. As the reaction proceeded for each experiment color was recorded and that indicated either a positive or negative control for each solution.