Amino Acid TERMS

• The genetic code is composed of nucleotide triplets. In other words, three nucleotides in mRNA (a codon) specify one amino acid in a protein.
• The code is non-overlapping. This means that successive triplets are read in order. Each nucleotide is part of only one triplet codon.
• The genetic code is unambiguous. Each codon specifies a particular amino acid, and only one amino acid. In other words, the codon ACG codes for the amino acid threonine, and only threonine.
• The genetic code is degenerate (redundant!). In contrast, each amino acid can be specified by more than one codon.
• The code is nearly universal. Almost all organisms in nature (from bacteria to humans) use exactly the same genetic code. The rare exceptions include some changes in the code in mitochondria, and in a few protozoan species.