Although each codon is specific for only one amino acid (or one stop signal), the genetic code is described as degenerate, or redundant, because a single amino acid may be coded for by more than one codon.

What causes the genetic code to be degenerate?

degenerate code definition. A code in which several code words have the same meaning. The genetic code is degenerate because there are many instances in which different codons specify the same amino acid. A genetic code in which some amino acids may each be encoded by more than one codon.

Which codons are degenerate?

Though phenylalanine, tyrosine, and cysteine are encoded by two codons each, phenylalanine shares a twofold degenerate codon box with leucine, which is one of the three amino acids encoded by six codons.