Reading the Genetic Code
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
original 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).
Figure after © 2004 by Griffiths et al. ; text © 2024 by Steven M. Carr