In this experiment, you will perform a series of tests to determine the presence of sugar, starch, lipids, and proteins for a variety of samples and determine the identity of an unknown.
Learning Objectives
Upon completion of this laboratory, you will be able to:
- Define protein, carbohydrate, lipid, and nucleic acid.
- Define a dehydration reaction and relate this reaction to the structure of a macromolecule.
- Describe the essential and nonessential amino acids that make up proteins.
- Compare and contrast simple and complex carbohydrates and how they are utilized metabolically.
- Describe the nucleotides in both DNA and RNA.
- List reagents used to identify biological macromolecules.
- Perform qualitative tests to determine the presence of lipids, sugars, proteins, and starch in a variety of samples.
- Identify an unknown through its composition of macromolecules.
Exercise 1: Starch and Sugar
Questions:
A. In each of the two tests (starch and sugar) a positive and negative control was used. What was the positive control in each of the tests and what was the negative control? Explain your answers.
B. Did the Benedict's test for reducing sugars net a positive or negative result for milk? Research the sugar content of milk and the definition of a reducing sugar to explain if your result is what you would expect.
C. Based on your results, is sugar and/or starch present in your Unknown? Use your results to explain your answer.
Exercise 2: Proteins and Lipids
In this exercise you will test a variety of samples for the presence of proteins (dipeptide bonds) and lipids.
Questions
A. Review the Data Tables in Exercises 1 and 2. Compare the results of the Unknown for all tests to the results for the various known samples to determine the identity of the Unknown. Explain the identity of the Unknown using your experiment results in the exercises to help explain and support your answer.
B. Eggs are known to contain cholesterol, which is a lipid. Did your experiment results indicate a presence of lipids in the albumin solution? Think about this result and where cholesterol is present in eggs to explain how your results support or reject cholesterol in eggs. How could you test this? Explain the experiment that you would perform to test this.
Attachment:- Biological Macromolecules.rar