What does the anticodon match up to when it joins the chain?

The anticodon is a sequence of three nucleotides found on a tRNA molecule that pairs with a complementary codon on an mRNA strand during translation. When the tRNA joins the growing polypeptide chain, the anticodon matches up with the codon on the mRNA, ensuring the correct amino acid is added to the chain according to the genetic code. This base pairing is crucial for accurate protein synthesis.