mRNA

The information in a gene sequence of DNA is copied into a new mRNA molecule. Ribosomes in the cytoplasm process the mRNA and direct the addition of amino acids to build a protein.

Signal Codon

AUG is the codon for methionine and is also the start codon. The ribosome starts translation, the assembly of a protein out of amino acids when it encounters the start codon in the mRNA.

Non-signal codons

Each three-letter sequence of mRNA nucleotides corresponds to a specific amino acid. There are 20 different amino acids, and the mRNA decides how the ribosome will build the amino acids into a protein.

Signal Codon

Any of these stop codons—UAA, UAG, or UGA— are recognized as a stop signal by the ribosome to stop protein synthesis. It is the final crucial step in the production of complete proteins.