AnticodonPairs with a matching codon on the mRNA by complementary base pairing.
CodonEach codon on the mRNA calls for one amino acid. The codon UUC pairs with the anticodon of the tRNA that carries phenylalanine.
Amino acidEach tRNA carries one specific amino acid. An enzyme called an aminoacyl tRNA synthetase attaches it.
Acceptor stemThe two ends of the tRNA strand base-pair to form this stem. The amino acid is attached at its 3′ end.
CCA tail (3′ end)The amino acid is bonded to the last base of this tail.
The loops 4
Anticodon loopA five-base-pair stem ending in the loop that contains the anticodon.
D loopA short stem ending in a loop, which often has dihydrouridine. That is a modified base written D.
TΨC loopNamed for the bases T, Ψ and C in the loop. Ψ: pseudouridine, a modified uridine.
Variable loopIt sits between anticodon loop and TΨC loop. In some tRNAs it is long enough to form a stem of its own.
How this list was compiled: Every name checked on 2026-09-30 against two of these, text only: Wikipedia, Transfer RNA (Structure: acceptor stem, CCA tail, D loop, anticodon loop, TΨC loop, variable loop, anticodon), https://en.wikipedia.org/wiki/Transfer_RNA; Proteopedia, Transfer RNA (tRNA) (cloverleaf of four stems, acceptor stem, anticodon loop, D-loop, TΨC-loop, variable loop, L shape), https://proteopedia.org/wiki/index.php/Transfer_RNA_(tRNA); OpenStax Biology 2e, 15.4 and 15.5 (the anticodon at one end and the amino acid at the other, the anticodon of the phenylalanine tRNA paired with the codon UUC, aminoacyl tRNA synthetases), https://openstax.org/books/biology-2e/pages/15-4-rna-processing-in-eukaryotes; OpenStax Microbiology, 11.4 (the CCA amino acid binding end at the 3′ end), https://openstax.org/books/microbiology/pages/11-4-protein-synthesis-translation. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work
How it works
A transfer RNA is one strand folded back on itself. This drawing lays it flat as the cloverleaf, the way the yeast phenylalanine tRNA is drawn in textbooks.
Read the full guide
Start with the two working ends
Numbers 1 to 3 are what a tRNA is for: the anticodon at the bottom pairs with a codon on the mRNA, and the amino acid rides at the top. Numbers 4 to 9 are the structure that holds them apart: the acceptor stem and its CCA tail, then the loops. Each loop is asked together with its stem. In the cell the cloverleaf folds again into an L shape, with the anticodon at one end and the amino acid at the other.
Thick lines are the strand; thin rungs are base pairs.
The tail at the 3′ end always reads C, C, A.
Questions and answers
What are the parts of a tRNA molecule?
An acceptor stem ending in a CCA tail, where the amino acid attaches; a D loop; an anticodon loop holding the three-base anticodon; a small variable loop; and a TΨC loop.
What does the anticodon of a tRNA do?
It is three bases that pair with a matching codon on the mRNA. That is how the right amino acid is brought to each codon during translation.
Where does the amino acid attach to a tRNA?
At the 3′ end. The strand ends in three unpaired bases, CCA, and the amino acid is bonded to the last one. An aminoacyl tRNA synthetase makes the bond.
Why is tRNA drawn as a cloverleaf?
The strand pairs with itself in four stems, three of them ending in loops, which looks like a cloverleaf when drawn flat. In the cell it folds further into an L shape.