The cloverleaf model of tRNA is a model that depicts the molecular structure of tRNA. The model revealed that the chain of tRNA consists of two endsâÂÂsometimes called "business ends"âÂÂand three arms. Two of the arms have a loop, D-loop (dihydro U loop) and TÃÂc-loop with a ribosome recognition site. The third arm, known as the "variable arm", has a stem with optional loop. One end of the chains (with a double stranded structure in which the 5' and 3' ends are adjacent to each other), the amino acids acceptor stem, usually attaches to amino acids and such reactions are often catalyzed by a specific enzymes, aminoacyl tRNA synthetase. For example, if the amino acid that attach to the end is phenylalanine, the reaction will be catalyzed by phenylalanine-tRNA synthase to produce tRNA<sup>phe</sup>.
The other endâÂÂthe bottom often called the "DNA arm"âÂÂconsists of a three base sequence that pairs with a complementary base sequence in a mRNA.