tRNAs have a specific sequence (CCA) at their 3' end where amino acids are attached. The amino acids link to the ribose of the terminal adenosine in this sequence. The opposite end of the tRNA, which has a structure called the anticodon loop, matches up with the mRNA template by pairing complementary bases. This ensures that the correct amino acid is added according to the mRNA code; the anticodon on a tRNA can pair with one or a few specific codons on the mRNA. tRNA also fold into a similar compact L shape, which helps them fit properly onto ribosomes during the process of translating genetic information into proteins. This specific shape is important for the tRNAs to function correctly during translation.