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Biological Polymers and Reactions

Sep 6, 2025

Overview

This lecture explains how biological polymers are built from monomers through dehydration synthesis and broken down through hydrolysis.

Biological Polymers and Monomers

  • Many biological molecules are polymers made from repeating subunits called monomers.
  • Proteins are polymers formed from amino acid monomers.
  • Complex carbohydrates are polymers formed from glucose monomers.

Dehydration Synthesis

  • Dehydration synthesis is the process where monomers join to form polymers.
  • Each monomer contributes either a hydrogen (H) or a hydroxyl group (OH) during the reaction.
  • The hydrogen and hydroxyl group combine to form a water molecule (H₂O).
  • A bond forms between the two monomers as water is released.

Hydrolysis

  • Hydrolysis is the process that breaks a polymer into its monomer subunits.
  • Water is added to break the bond between monomers.
  • The hydroxyl group from water attaches to one monomer and the hydrogen attaches to the other.
  • Hydrolysis means "to break with water."

Recap of Reactions

  • Dehydration synthesis joins monomers into polymers and releases water.
  • Hydrolysis adds water to split polymers into monomers.

Key Terms & Definitions

  • Monomer — a small molecule that can join with others to form a polymer.
  • Polymer — a large molecule made of repeating monomer units.
  • Dehydration Synthesis — reaction where monomers join to form polymers, releasing water.
  • Hydrolysis — reaction that uses water to break polymers into monomers.

Action Items / Next Steps

  • Review examples of dehydration synthesis and hydrolysis reactions in course materials.