1.3 - Introduction to Biological Macromolecules

The Big Four

Living organisms rely on four major classes of large biological molecules (macromolecules):

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic Acids

These are called macromolecules because they are relatively large compared to other molecules.

Polymers and Monomers

• Many of these macromolecules are polymers, which are long chains built from smaller repeating units called monomers.

• Think of it like a beaded necklace: the monomers are the individual beads, and the polymer is the entire necklace.

Building and Breaking Polymers

• Dehydration Synthesis (Condensation Reaction): Monomers are linked together to form polymers by removing a water molecule (-OH from one monomer and -H from another). This creates a new covalent bond.

• Hydrolysis: The opposite of dehydration synthesis. Polymers are broken down into monomers by adding a water molecule, splitting the covalent bond.