DNA Translation

Act I: Initiation
-mRNA is now transported from the nucleus to the cytoplasm.
-the ribosome, where protein synthesis takes place, has two ribosomal units (small and large).
-the ribosome also has one site for the binding of mRNA and three sites for the binding of tRNA (P site, A site, E site).
-during initiation, mRNA, tRNA and ribosomal units come together.
-the first tRNA binds to the P site of the large ribosomal unit.

Act II: Elongation:
-codon recognition: the anticodon of a new tRNA binds to the codon of mRNA in the A site.
-peptide bond formation: the polypeptide attached to tRNA in the P site moves and bonds with the amino acid in A site. This process of peptide bond formation is proceeded with the assist of rRNA.
-translocation: the tRNA in the A site with its polypeptide attached moves over to P site. The previous tRNA in P site exits through E site.

Act III: Termination
-translation ends when one of the stop codons (UAG, UGA, UAA) reachea the A site of the large ribosomal unit.
-A release factor binds to the stop codon and breaks up the peptide bond through hydrolysis between the polypeptide and tRNA in P site.
-the polypeptide is now released.