Translation

Translation

Synopsis: Translation is the process by which a protein is synthesized from the information contained in messenger RNA (mRNA).

Characters: tRNA, small and large ribosomal unit, codons, start and stop codons, anticodons, rRNA, ribosome

Plot: Initiation, Elongation, Termination

ACT I: Initiation

• mRNA, the tRNA with the first amino acid (methionine)and two ribosomal subunits(small and large) gather together.
• Small ribosomal subunits bind with the mRNA and the tRNA that has the methionine amino acid and then binds to the start codon (AUG).
• Initiation factors bring large subunits such as the tRNA to take over the P site.

Act 2 - Elongation 

• Anticodons of tRNA molecules bind to mRNA codons in the A site of the ribosome. 
• rRNA catalyzes peptide bond formation among the polypeptide located in the P site with the amino acid in the A site.
•  The tRNA molecule with the polypeptide is moved from the A site to the P site (translocation), and codons are matched with their respective anticodons in the 5' to 3' direction. After that, it exits at E site.
• Process is repeated by entering a new codon at site.

Act 3 - Termination 

• Translation continues until ribosome reaches 1 of the 3 stop codons (UGA, UAG and UAA).
• Termination proteins bind to the ribosome and a release factor cuts the polypeptide chain from the last tRNA. 
• Large and small subunit separates as ribosome released from mRNA.

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