Transcription

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Understanding:

•  Transcription is the synthesis of mRNA copied from the DNA base sequence by RNA polymerase

    
Transcription is the process by which an RNA sequence is produced from a DNA template

  • RNA polymerase separates the DNA strands and synthesises a complementary RNA copy from one of the DNA strands
  • When the DNA strands are separated, ribonucleotide triphosphates align opposite their exposed complementary base partner
  • RNA polymerase removes the additional phosphate groups and uses the energy from this cleavage to covalently join the nucleotide to the growing sequence
  • Once the RNA sequence has been synthesised, RNA polymerase detaches from the DNA molecule and the double helix reforms


The Role of RNA Polymerase in Transcription

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Gene

The sequence of DNA that is transcribed into RNA is called a gene

  • The strand that is transcribed is called the antisense strand and is complementary to the RNA sequence 
  • The strand that is not transcribed is called the sense strand and is identical to the RNA sequence (with T instead of U)


Transcription of genes occur in the nucleus (where DNA is), before the RNA moves to the cytoplasm (for translation)


Overview of Transcription