The nucleotide triplet that encodes an amino acid is called a codon. Each group of three nucleotides encodes one amino acid. Since there are 64 combinations of 4 nucleotides taken three at a time and only 20 amino acids, the code is degenerate (more than one codon per amino acid, in most cases).

How are amino acids read in a strand of mRNA?

tRNAs bring their amino acids to the mRNA in a specific order. This order is determined by the attraction between a codon, a sequence of three nucleotides on the mRNA, and a complementary nucleotide triplet on the tRNA, called an anticodon. This anticodon also specifies the particular amino acid that the tRNA carries.

Does DNA or mRNA code for amino acids?

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).