Explain how changing one base in a DNA sequence may result in a non-functional protein being produced.

Changing one DNA base will alter one triplet in the DNA code. As each triplet codes for an amino acid this may result in a change to the primary structure of the protein produced. If the changed amino acid was involved in ionic or disulphide bonding then the secondary and tertiary structure of the protein will also change. This may change the shape of the proteins receptor sites and make it non-functional.