Dehydration Synthesis & Hydrolysis

Biological Macromolecules

• Hydrocarbons form the framework for the 4 classes of macromolecules:
  • Proteins
  • Carbohydrates
  • Nucleic Acids
  • Lipids

Polymers and Monomers

• Three classes of organic molecules are polymers: carbohydrates, nucleic acids, and proteins.
• Organisms are unique based on the arrangement of monomers used to make polymers.
• A variety of polymers can be built from a small set of monomers.
• Polymer: Monomer
  • Proteins: Amino acids
  • Carbohydrates: Simple sugars (monosaccharides)
  • Nucleic acids: Nucleotides

Dehydration Synthesis

• Polymers are formed through dehydration synthesis.

• Two monomers combine, a water molecule is removed, and a polymer is created.

• Dehydration: removing a water molecule.

• Synthesis: combining separate parts to make a new whole.

• The reaction can be represented as:

  $\text{molecule 1} + \text{molecule 2} \rightarrow \text{new molecule} + H_2O$

Hydrolysis

• New molecules can be formed by breaking existing molecules apart, allowing the products to react with other molecules. This process is called Hydrolysis.

• A water molecule is added to a molecule, causing it to split apart.

• The H and OH groups from the water combine with each product.

• The reaction can be represented as:

  $\text{original molecule} + H_2O \rightarrow \text{molecule 1} + \text{molecule 2}$

Dehydration Synthesis vs. Hydrolysis

• Dehydration Synthesis:

  $\text{Monomer} + \text{Monomer} \rightarrow \text{Polymer} + \text{Water}$

  Reactants: Monomers
  Products: Polymer and Water

• Hydrolysis:

  $\text{Polymer} + \text{Water} \rightarrow \text{Monomer} + \text{Monomer}$

  Reactants: Polymer and Water
  Products: Monomers