protein synthesis

• Protein synthesis


  The process of creating proteins in cells
• Transcription

  1. Produces pre-mRNA from DNA in eukaryotes

  2. Produces mRNA from DNA in prokaryotes

  3. RNA polymerase breaks hydrogen bonds between complementary DNA bases, exposing both strands

  4. RNA polymerase adds RNA nucleotides to complementary bases on template strand

  5. RNA polymerase moves along entire DNA strand until pre-mRNA (or mRNA) is complete

  6. DNA helix behind is reattached, original helix DNA and mRNA is left
• Splicing


  Occurs in eukaryotes only
• Splicing

  1. Introns (non-coding genes) are removed from pre-mRNA

  2. Exons (coding genes) are left in the mRNA strand
• Prokaryotes do not have introns and do not undergo splicing
• Translation

  1. Ribosome attaches to mRNA strand

  2. tRNA molecule with complementary anticodon binds to a codon on mRNA, bringing amino acid with it

  3. Ribosome joins the two amino acids together with a condensation reaction (help from ATP and an enzyme) forming a peptide bond

  4. Ribosome moves along mRNA until polypeptide chain is complete