RNA and protein synthesis

• Structure of mRNA

  Single polynucleotide strand
• Function of mRNA

  Made during transcription

  Carries genetic code from DNA to the ribosomes
• tRNA structure

  Single polynucleotide chain

  Hydrogen bonds between base pairs hold shape

  Anti codon at one end and amino acid binding site at the other

  Clover shape
• Transcription

  1. RNA polymerase binds at start codon. DNA helicase breaks hydrogen bonds containing gene for desired protein
  2. RNA moves along template strand, joins free RNA nucleotides to template strand forming pre mRNA
  3. DNA bases re-joined behind RNA polymerase
  4. RNA polymerase stops and detaches at stop codon
  5. Pre-mRNA spliced before leaves nuclear pore to find a ribosome
• Translation

  1. Ribosome attaches to start codon on mRNA. tRNA with complementary anti codon with start codon binds to mRNA
  2. Two at a time moves along next codon etc
  3. Condensation reaction between two amino acids=polypeptide bond= forming polypeptide
  4. Goes until stop codon reached and polypeptide formed
• What does mRNA contain


  Ribose

  Phosphate

  Base