The genetic code
Background: Making a protein
- In transcription, the DNA sequence of a gene is "rewritten" in RNA. In eukaryotes, the RNA must go through additional processing steps to become a messenger RNA, or mRNA.
- In translation, the sequence of nucleotides in the mRNA is "translated" into a sequence of amino acids in a polypeptide (protein chain).
- Most codons specify an amino acid
- Three "stop" codons mark the end of a protein
- One "start" codon, AUG, marks the beginning of a protein and also encodes the amino acid methionine