Lecture 1 – Types of Macromolecules

Macromolecules:

Macromolecules are defined as large molecular structures made up of small units of recurring molecules.

Examples:

1. Carbon forms layered macromolecular structure in graphite. Each carbon atom is bonded by 3 other carbon atoms. The layers can slide oven one another to give graphite is flaky and lubricating property. Since, each carbon is bonded with 3 other carbon atoms, 1 electron is free per carbon atom. This free electron gives graphite its electrical conductivity, when a potential difference is applied perpendicular to the carbon layers.
2. Carbon forms a tetrahedral molecular structure in diamond. Each carbon atom is bonded with 4 other carbon atoms with strong intermolecular forces of attraction. This tetrahedral bonding of carbon in diamond, makes diamond the strongest matter known to mankind.  
3. Silicon forms a tetrahedral macromolecular structure with oxygen in sand. Sand is a macromolecule where the repeating unit is silicon dioxide; SiO₂.
4. Polyethene forms a macromolecular structure having chains of – CH₂ – CH₂- repeating units.
5. Carbohydrates are natural macromolecules having repeating units of carbon, hydrogen and oxygen in their molecular chains.
6. Fats are natural macromolecules having the –COO– or ester linkage in between their chains.
7. Protein are natural macromolecules having the –NH-CO- or amide linkage in between their chains.