Transcript Separating and Identifying Amino Acids with Paper

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