The genetic
code is a messenger RNA
(mRNA) code read in three-letter
blocks (codons) in the
5' 3' direction.
The layout of the code above is the
standard 4 x 4 x 4 presentation. To read the mRNA codon 5'-ACG-3' :
Read the A across the first-letter block on
left-hand side of the table, then
Read the C down the second-letter column across
the top of the table, finally
Read G as the fourth line in that block, from the
third-letter line on right-hand side of the table
The
codon 5'-ACG-3'
codes for the amino acid Thr (Threonine).