BackThe Structure and Function of Large Biological Molecules
Study Guide - Smart Notes
Tailored notes based on your materials, expanded with key definitions, examples, and context.
The Structure and Function of Large Biological Molecules
Macromolecules: Types and Importance
Macromolecules are large, complex molecules essential for life. They are primarily composed of smaller subunits called monomers. The four main classes of biological macromolecules are:
Proteins
Lipids
Carbohydrates
Nucleic acids
Cells join smaller organic molecules together to form these large macromolecules. These macromolecules may be composed of thousands of atoms. Large molecules are made by linking together smaller molecules called monomers.
Polymerization: Building Macromolecules
Most macromolecules (except lipids) are polymers, which are long chains of monomers. The process of forming polymers from monomers is called polymerization.
Monomer: A small molecule that can join with others to form a polymer.
Polymer: A large molecule made up of repeating monomer units.
Example: Glucose (a monomer) can join with other glucose molecules to form starch (a polymer).
Dehydration Synthesis (Condensation Reaction)
Dehydration synthesis is a chemical reaction in which two or more monomers combine to form a polymer, with the removal (loss) of a water molecule. This process is essential for building complex macromolecules in cells.
Key Point: Each time a monomer is added to a growing polymer chain, a water molecule is released.
Equation:
Example: Formation of a disaccharide (like sucrose) from two monosaccharides (glucose and fructose) by releasing water.
Hydrolysis: Breaking Down Polymers
Hydrolysis is the process by which polymers are broken down into monomers by the addition of a water molecule. This reaction is the reverse of dehydration synthesis and is crucial for digestion and cellular metabolism.
Key Point: Water is used to break the bonds between monomer units in a polymer.
Equation:
Example: Digestion of starch into glucose monomers in the human body.
