Enter a DNA template strand (3'→5') or coding strand (5'→3').
Transcription converts DNA to mRNA: the coding strand (5'→3') has the same sequence as mRNA (with U replacing T). The template strand (3'→5') is the complement. RNA polymerase reads the template strand 3'→5' and synthesizes mRNA 5'→3'. Translation at the ribosome reads mRNA in triplet codons, each specifying an amino acid. AUG = start codon (Met), UAA/UAG/UGA = stop codons. The genetic code is degenerate (64 codons for 20 amino acids + stops), meaning most amino acids are encoded by multiple codons. This central dogma — DNA→RNA→Protein — is fundamental to all life (with exceptions in retroviruses and prions).