By the end of this lab, you will be able to:
- Distinguish between positive and negative controls and explain their use in an experiment
- List the polymers and monomers of the four categories of biological macromolecules
- Name the colourimetric reagents used for identifying specific biological macromolecules
- Predict and interpret the results of a colourimetric test to determine the presence or absence of a specific macromolecule
Required prior knowledge and textbook readings:
- Organic macromolecules and their structural components
- Experimental design and variables
- Chapter 2, Section 2.3: Biological Molecules in Concepts of Biology textbook
Introduction:
In this lab, you will review the results of a series of experiments to assess the presence or absence of biological macromolecules in various substances.
Colourimetric reagents will be used to test for the presence of biological macromolecules. These reagents react with specific types of molecules to produce dramatic colour changes. If the reagents do not change colour, this indicates the absence of that molecule. The expected results of each colourimetric test will be outlined throughout the lab.
In order to ensure that our experimental results are not due to other factors, we will be using negative and positive control groups in our experimental design:
- Negative control groups are used in an experiment as a basis for comparison. Typically, there will be no change or response expected in that group, as no independent variable will be present.
- Positive control groups are also used as a basis for comparison. Typically, there is an expected positive response, as they usually have a high amount of the independent variable, or another variable known to cause a change.
You will need to identify negative and positive controls for each of the following experiments.
Part 1: Testing for Lipids
abc
Part 2: Testing for Proteins
abc
Part 3: Testing for Simple Carbohydrates
abc
Part 4: Testing for Complex Carbohydrates
abc
Assignment:
If required by your instructor, you can download the assignment for the Macromolecules lab here [need to link to file when available]. Note that the file download works best using Microsoft Edge or Mozilla Firefox web browsers (not Google Chrome). Once you have completed the assignment, submit the file to your instructor as per their instructions.