In transcription, the double-stranded DNA is copied into single-stranded RNA by the enzyme RNA polymerase. In eukaryotes, the RNA is likely to be modified after transcription by splicing. Finally, the RNA is inserted into ribosomes.
The ribosomes translate the RNA into protein, using the genetic code to build a chain of amino acids, linked by peptide bonds. The individual amino acids are delivered by tRNAs that match the current codon (nucleotide triplet) of the RNA. The nascending polypeptide chain folds, either by itself or with the assistance of chaperone proteins, into its (final) tertiary structure.