The sequence of bases on mRNA is the genetic code. Each set of three bases corresponds to the bases on one tRNA molecule (the anticodon) the top of the tRNA molecule is attached to an amino acid, in this way every triplet of bases- called a codon- codes for an amino acid.
The genetic code is:
- Universal- it is the same in all organisms
- Non-overlapping- each base is read only once
- Degenerate- amino acids have several different codons that code for them
tRNA is a folded strand that creates a shape with the anti-codon on one side and the attachment site for an amino acid on the other.