Natural Polymers and DNA [H]

This lesson covers natural polymers and the structure of DNA as required by the AQA GCSE Chemistry specification (5.8.2). This is Higher Tier only [H] content. While synthetic polymers like poly(ethene) and nylon are manufactured by humans, nature also produces polymers — including proteins, starch, cellulose, and DNA. Understanding natural polymers bridges chemistry and biology.

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What Are Natural Polymers?

Natural polymers (also called biopolymers) are polymers that are produced by living organisms. They are formed by condensation polymerisation — monomers join together with the loss of water molecules.

Natural Polymer	Monomer(s)	Type of Link	Found In
Proteins	Amino acids	Peptide (amide) link –CONH–	Muscles, enzymes, hair, skin
Starch	Glucose	Glycosidic link	Plants (energy storage)
Cellulose	Glucose	Glycosidic link	Plant cell walls
DNA	Nucleotides	Phosphodiester link	Cell nuclei (genetic material)

All of these natural polymers are formed by condensation reactions, where a small molecule (water) is released each time a bond forms between monomers.