protein synthesis

• transcription in nucleus

  1. DNA helicase unzips double helix, exposing bases
  2. free mRNA nucleotides line up complimentary to the template strand bases with u replacing t and temporary hydrogen bonds forming
  3. RNA polymerase joins the mRNA backbones creating a strand of mRNA
  4. mRNA strand then leaves nucleus through nuclear pore and travels to ribosome
• translation in ribosome


  Translation in Ribosomen
• Translation in ribosome


  1. mRNA travels to ribosome from nucleus

  2. mRNA attaches to ribosome

  3. mRNA delivers genetic codes

  4. Triplets of bases on mRNA (codons) complementary base pair to triplets on tRNA (anticodons)

  5. Hydrogen bonds form between mRNA and tRNA

  6. Amino acids held close together

  7. Peptide bond forms

  8. tRNA lets go

  9. Ribosome shifts along to next 2 codons

  10. Repeats until stop codon

  11. Polypeptide released into cytoplasm
• Codon


  Triplets of bases on mRNA that code for one of 20 amino acids
• Anticodon


  Triplets on tRNA that complementary base pair with codons on mRNA
• tRNA

  • Lots of tRNA molecules in cytoplasm
  • One end has anticodon, other end has amino acid
• Hydrogen bonds between mRNA and tRNA hold the amino acids close together so a condensation reaction occurs and a peptide bond forms