Tag Archives: Messenger RNA

DNA & Heredity Transcription & Translation

Protein Synthesis Involves Transcription & Translation

  • The 2 steps of protein synthesis:
    Process Where Major Components Notes
    Transcription In the nucleus DNA gene
    RNA polymerase
    Gene is activated.
    A copy of the code is made from RNA (m-RNA)
    m-RNA leaves the nucleus, goes to cytoplasm.
    Translation In the cytoplasm, on the ribosomes m-RNA
    Peptidyl transferase enzyme
    Transfer RNAs
    Ribosome decodes the m-RNA and makes the correct protein.
  • Keeping the main copy of the genes in the nucleus protects it from damage
  • There are many DNA repair mechanisms in the nucleus


The Polymerase Chain Reaction (PCR) Can Make Millions of Copies of DNA in a Short Time

  • The polymerase chain reaction (PCR) is a rapid way of amplifying (duplicating) specific DNA sequences
  • Method was devised by Kary Mullis of Cetus Corporation, Emeryville
    • He recieved a $20,000 bonus and later a Nobel Prize
    • Later the patent was sold to Hoffman-LaRoche for $300,000,000
  • DNA heated to high temperature is not destroyed; separates into single strands, but reforms helix when cooled
  • PCR Method:
    • DNA to be amplified is put into solution containing:
      • Short DNA “primers” which can bind to the 3′ ends of the DNA