Protein Synthesis

• Purpose

  Building proteins (made of amino acids)
• Transcription

  Occurs in the nucleus

  A gene's DNA sequence is copied into mRNA

  
  

  RNA polymerase binds to the promoter, unwinds the DNA strand (initiation), and synthesizes a complementary mRNA molecule. The mRNA molecule is created through base pairing (elongation). The RNA polymerase detaches from the DNA and releases the mRNA (termination).
• Translation

  Occurs in the cytoplasm

  Converting the mRNA sequence into an amino acid sequence to form a protein

  
  

  A process involving ribosomes, tRNA and protein factors

  The start codon, adenine-uracil-guanine, signalling protein synthesis (initiation).

  The ribosome moves along the mRNA molecule, recognising each codon with a specific amino acid. The ribosome catalyses peptide bond formation, creating a growing polypeptide chain (elongation). The process ends with a stop codon, releasing the newly synthesised polypeptide (termination).