BIOL 1106Professor StinemetzLab #3 – Chemical Compositionof Cells1
2IntroductionIn living organisms and in common substances that we use daily,the large biological molecules –proteins, lipids, nucleic acids,and carbohydrates– are present. By utilizing different chemicalreagents, and for one experiment a simple brown paper towel test,you will be able to determine (with the exception of nucleic acids),if these large macromolecules are present in a variety ofsubstances.In all the experimental procedures water will be thecontrol. Acontrol is a substance included in the experiment that we alreadyknow does not contain the macromolecule we are testing for. Thisis important to ensure the accuracy of the experiment.
3IntroductionA differentreagentwill be used for each molecule we are testingfor. This reagent will have certain chemical properties, and therewill be a visible change in the reagent when it interacts with themolecule we are testing for. Apositive testfor a molecule will beindicated by acolor changeas compared with the control(meaning the substance we are testing for is present). If thereagent is the same color as the control, the result is a negativetest, and we know that the substance we are testing for is notpresent.