Translation: The Three-act Play

Initiation

Act 1: Initiation

• The mRNA comes to the cytoplasm, with a starting condon, which is  AUG, on it.
• A small ribosomal subunit binds with mRNA.
• A tRNA (transfer RNA) carrying a specific amino acid, Met, at one end and having a specific nucleotide triplet, anticodon UAC, at the other end comes to bind with the starting codon.
• Initiation factors brings the large ribosomal subunit to mRNA, placing the tRNA in the P site.

Elongation

Act 2: Elongation

• Another tRNA carrying amino acid recognizes its corresponding condon at the A site.
• An RNA molecule catalyzes the formation of a peptide bond between the polypeptide in the P site withe the new amino acid in the A site.
• The polypeptide chain is transferred to the tRNA at the A site. 
• The ribosome moves the tRNA with the attached poplypeptide form the A site to the P site. This process need energy provided by GTP.
• The first tRNA enters the E site, and as the third tRNA attaches to the A site, it exits the E site to the cytoplasm to pick another amino acid.
• The process keeps going on.

Termination

Act 3: Termination

• When one of the three stop condons(UAG, UAA and UGA) reaches the A site, a release factor cut the bond between the polypeptide chain and its tRNA at the P site.
• Polypeptide, which is known as protein, is released.
• Translation complex disassembles.