Translation - DNA, RNA & the Codon Table Step by Step

Walking the mRNA codon by codon through the table spells the protein.

highlighted = computed this step

Read each codon, look up its amino acid

Translation walks the mRNA one codon at a time and writes down the amino acid the table gives for each. Here AUG·GCA·UGC·AAA spells the peptide MACK.

\text{AUG}\cdot\text{GCA}\cdot\text{UGC}\cdot\text{AAA} \longrightarrow \text{M}\,\text{A}\,\text{C}\,\text{K}

Each letter is the table's answer

Every amino acid below is the literal codon-table lookup of the three bases above it — the first codon AUG gives methionine (M).

\text{AUG} \to \text{Met (M)}, \quad \text{GCA} \to \text{Ala (A)}

A stop codon ends translation

The codon after the peptide, UAA, is a stop: it names no amino acid, so the chain ends and the protein is MACK. Honesty note: the cell does this with a ribosome and transfer RNAs; we show only the symbolic lookup, not that machinery.

\text{UAA} \to \text{stop}, \quad \text{protein} = \text{MACK}