The mRNA basesare grouped into sets of three, called codons. Each codon has a complementary set of bases, called an anticodon. Anticodons are a part of transfer RNA (tRNA) molecules. Attached to each tRNA molecule is an amino acid -- in this case, the amino acid is methionine (met).What does tRNA use to match to the mRNA?
By themselves, ribosomes cannot form a protein when the mRNA makes contact. The anticodon, a string of three key bases on the tRNA, match with three bases on the mRNA message called the codon. That is only the first function of tRNA, as each molecule also carries with it an amino acid which matches the mRNA codon.