How are proteins and nucleic acids related? if one nucleotide were changed within the nucleic acid molecule, how could that affect the protein being produced?

The relationship between the nucleic acid and protein is this: the nucleic acid contains the series of codon which determines the sequences of amino acids in a protein. Each codon of nucleic acid code for a particular amino acid.
If one nucleotide is change within the nucleic acid that is coding for a particular protein, another protein entirely may be produced and this will alter the original function of this protein. This can lead to fatal consequences.