Translation

1) Initiation

• mRNA transferred to the ribosomes
• Initiation factors (protein) assemble 
• Small ribosomal sub-unit - attaches to mRNA near start codon (AUG)
• Initiator tRNA - first to bind with codon (carrying methionine amino acid)
• mRNA
• Large ribosomal sub-unit - to form active ribosome
• 3 binding sites for tRNA 
• P (peptide) - contains tRNA with polypeptide attached
• A (amino acid) - contains tRNA with next amino acid added to polypeptide chain
• E (exit) - uncharged tRNA with no amino acid attached exits
• Moves from 5' to 3'

2) Elongation

• tRNA anticodons bind to mRNA codons in the 'A' site of the ribosome
• Initiating transfer RNA binds to the 'P' site
• tRNA recognizes the next codon and second amino acid moves to 'A' site
• Amino acid from tRNA joins amino acid by the tRNA that just entered 'A' site
• First transfer RNA is released
• Next transfer RNA moves to 'A' site and ribosome moves down one codon
• Second amino acid on tRNA in 'P' site transfers to third amino acid
• And Continues: Ribosome to move along mRNA and new amino acids are added to the growing polypeptide chain

3) Termination

• Terminates when mRNA reaches stop codon
• Stop Codons: UAA, UAG, UGA 
• Release factor (protein) cuts the polypeptide from last tRNA