Question: when a trna anticodon binds to an mrna codon?
Answer: A tRNA whose anticodon is complementary to this next mRNA codon is attracted to the ribosome and the mRNA. Once again, the polypeptide chain is transferred to the new tRNA, the empty tRNA is released, and the ribosome ratchets through the mRNA another three nucleotides, simultaneously shifting the tRNA as well.