Monomers

Organic compounds are typically composed of recurring subunits (monomers) which are covalently joined to form polymers

• The monomeric subunit of carbohydrates is a monosaccharide (single sugar unit)

• Nucleic acids are composed of repeating nucleotides (containing a sugar, phosphate and nitrogenous base)

• Proteins consist of linked chains of amino acids which differ according to a variable side chain (‘R’ group)

• Lipids do not contain monomers but certain types may be composed of distinct subunits (fatty acid chains)

Types of Monomers / Subunits

Polymerisation

Polymers can be formed from monomeric subunits via condensation reactions

• A hydroxyl group (-OH) on one monomer is combined with a hydrogen atom (-H) on another monomer 
  

• The two monomers become covalently bonded and a water molecule is produced as a by-product
  

Condensation Reaction

Condensation Reaction