Translation

• Translation occurs at the ribosomes. It joins amino acids to form polypeptides during interphase (G1)
• Ribosome Structure

  • 2 protein subunits
  • Ribosomal RNA (rRNA)
• Ribosomes read the mRNA code and joins amino acids in the correct sequence, makes a specific polypeptide
• 1. Ribosome "looks at" first codon (AUG)
  2. tRNA (transfer) molecule with complimentary codon delivers specific amino acid to the ribosome
  3. A second tRNA molecule delivers a 2nd amino acid
  4. Two amino acids are joined by a peptide bond (condensation reaction)
  5. first tRNA molecule leaves
  6. Ribosome moves along the mRNA to read the next codon. Complementary tRNA delivers the next amino acid. Amino acid is joined to the grown polypeptide chain via peptide bond.

  This repeats until a STOP codon is reached. No amino acid delivered=end of translation