Separating and Identifying Amino Acids with Paper Chromatography Lab #2
Procedures for finishing Lab #2 • Find your (2) Chromatography strips (Known & unknown) • Compare your strips with other classes • Note where the amino acid moved **If it is speared approximate its location using the other classes. • Measure the distances moved by the solvent and the amino acid • Calculate the Rf value and enter your value in the computer • Identify your unkown using all of the Rf values • Write up your lab report (Due: Thurs. 9/22)
Introduction/Background • Purpose of the lab and its importance toward our study of Biology. • What are the various ways that amino acids can be separated (use your research) • Why is paper chromatography being used for our setting? • How does this method work? • What are the goals for this lab?
Hypothesis & Preparations for Lab • Must be a clear statement of what you predict will happen. • Follow your prediction with reasons why you have made this statement • Identify the independent and dependent variables • Provide a list of materials needed to do this lab. Be sure the list is complete including size and number of items needed.
Method & Procedures • Write a step by step procedure indicating everything you did in this lab. • A bulleted list can be helpful • Use the handout I gave you as a starting point and make all of the necessary modifications to be as accurate as possible. • Someone reading this procedure should be able to follow these instructions and do exactly what you did. This would include: • How the data was obtained • How the data will be analyzed
Data- How to Organize it • Data table of all amino acids studied in the class • (2) chromatography strips (known and unknown) -each strip should be cut in half -stapled in your report -show where the solvent and amino acids moved to with the measured distances (cm) • Show the Rf value you calculated next to these strips • Be sure to explain how all of the data was obtained in your table
Lab # 2: Guidelines for Write Up • Title • Introduction/Background • Hypothesis • Independent & Dependent Variables • Materials (modify the list w/specifics) • Procedure (modify from what I gave you) • Data (both chromatography strips cut in half) • Data Table • Analysis w/ graph • Conclusion & Evaluation
Analysis • Graph your data (molecular weight vs. Rf or distance moved) • Review your hypothesis - were you right? • Explain what happened vs. what you predicted • Why were you wrong or right? • Explain how you interpreted your results (procedure & methods) • Look for any patterns, correlations, or relationships that might be significant • Were you able to identify the unknown? Explain
Sources of Error & Evaluation • What were some of the problems you encountered during the lab? • Why were your results different from others? • How can this lab be improved?
Lab # 2: Guidelines for Write Up • Title • Introduction/Background • Hypothesis • Independent & Dependent Variables • Materials (modify the list w/specifics) • Procedure (modify from what I gave you) • Data (both chromatography strips cut in half) • Data Tables • Analysis w/ graph • Conclusion & Evaluation