Learning Objectives for this lab:

Contents:

Submission:

    The exercises have been divided into three different submission forms.  Please submit your answers by Monday, 2/25 at midnight.

Navigation through this lab:

1. Read the materials needed page and get everything.
2. Read the introduction below.
3. Read the web page here that describes all the exercises.  It made more sense to have some of the descriptions with the submission forms, so you won't find everything here.
4. Read the submission forms and see what you will be needing to send me.
5. Do the experiments. 
6. Submit the forms by 2/25 at midnight.

Introduction

In this lab, you will be learning about macromolecules, which are types of organic molecules. Macromolecules are very large molecules (and are composed of smaller, building blocks). You will recall that there are four (4) major classes of macromolecules. These are:

You have already learned about macromolecules in lecture, so some of this information will be review.  But it may just be handy to have this all right here as you do the experiments.

Lipids

    All lipids share one common property – they are insoluble in water (meaning they will not mix with water). There are two types of lipids we will be investigating today:

triglycerides: your book calls these lipids "storage glycerides." Butter, Lard, and Oil are examples of molecules found in this class. The major function of triglycerides is for long-term energy storage. This function may make sense to you, as you probably know what happens if you eat more than your body requires—the energy in the excess food is stored as…fat!

steroids include cholesterol (shown at the right) and sex hormones.

Carbohydrates

    These macromolecules are mainly used to store chemical energy inside a cell. You have probably heard of the term "carbo-loading" which is often done by athletes prior to an event. The reason? To obtain as much energy as possible for use in the event. Carbohydrates can also function as structural units for cells.

Monosaccharides:

    These are the building blocks for carbohydrates and are referred to as simple sugars.  Monosaccharides are also used by the cell to create cellular energy. Examples of monosaccharides are glucose and fructose.

Polysaccharides:

    If more than two monosaccharides are joined together, the result is a polysaccharide. Polysaccharides serve two functions: they can be used as large sugar storage molecules or as structural molecules.

Proteins

    These macromolecules are composed of amino acid building blocks. The general structure of an amino acid is shown in this diagram. There are 20 different amino acids because the R group can represent any one of 20 different side groups.

    Amino acids bond together into long chains to create proteins.  Each protein has a unique combination of the various amino acids.  The ways that the chains fold up give each protein a unique shape and function.  Some functions for proteins include:

Note that shape and function go hand-in-hand.  For example, a membrane channel protein tends to be shaped like a tube, while an enzyme is shaped to match the chemicals it interacts with so that it can assist in chemical reactions.  Therefore, the shape of a protein must be maintained in order for it to serve its function.

Nucleic Acids

These macromolecules are composed of nucleotide building blocks. The general structure of a nucleotide is shown in this diagram. Note that it consists of 3 major parts: 1) a nitrogenous base; 2) a 5-carbon sugar; and 3) a phosphate group.

There are two major types of nucleic acids:

© 2006 STCC Foundation Press, content by Dawn A. Tamarkin, Ph.D.

Last changed: January 21, 2007