The aa-tRNA then fully enters the A-site, where its amino acid is brought near the P-site's polypeptide and the ribosome catalyzes the covalent transfer of the polypeptide onto the amino acid.
The aa-tRNA enters the A site, where its amino acid is brought near the P site's polypeptide chain, and the ribosome catalyzes the covalent transfer of the polypeptide onto the amino acid.