8.5 - Translation

• What’s translation ?


  The production of polypeptides from the sequence of codons carried by mRNA
• 1st step of translation?

  mRNA associates with a ribosome in the cytoplasm at its start codon
• 2nd step of translation?


  tRNA molecules with complementary anticodons move to ribosome and bind with the mRNA codons(the tRNA carry specific AA that the codon codes for)
• 3rd step of translation?


  This process repeats as the ribosome moves along the mRNA strand
• 4th step of translation?


  2 adjacent AA on their tRNA molecules are joined by peptide bonds using and enzyme and ATP which is hydrolysed to provide the required energy
• 5th step of translation ?


  As the 3rd codon is reached and the 3rd AA bonded, the first tRNA is released from its AA now free to collect other AA from the pool in the cell
• 6th step of translation?

  Process continues until polypeptide chain is complete and the ribosome reaches a stop codon where it separates from the mRNA
• What’s the ribosomes 2 roles in translation ?

  • provide a structure in which translation can occur
  • catalyse the reaction that links AA (peptide bonds)