Biological Macromolecules Lab Report

Biological Macromolecules

Hands-On Labs, Inc.
Version 42-0291-00-02

Lab Report Assistant

This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.

Exercise 1: Starch and Sugar

Data Table 1.Benedict’s Reagent Data.

Sample	Initial Color	Final Color	Reducing Sugar Present in Sample? Y or N
dH2O
Albumin
Unknown
Milk
Glucose

Data Table 2. Lugol’s Iodine Data.

Sample	Initial Color	Final Color	Starch Present in Sample? Y or N
dH2O
Albumin
Unknown
Milk
Starch
Raw Potato

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

Data Table 3. Biuret’s Reagent Data.

Sample	Initial Color	Intermediate Color	Final Color	Protein Present in Sample? Y or N
dH2O
Albumin
Unknown
Milk

Data Table 4. Lipid Observations.

Sample	Sample Observations	Lipid Present in Sample? Y or N
Distilled water
Albumin
Unknown
Milk
Vegetable oil

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.