Protein Synthesis

• Protein Synthesis takes place in two stages, one called transcription and one called translation

  • Transcription happens in the Nucleus
  • Translation happens in the Ribosomes
• In TransCRIPTION:

  1. Part of the DNA helix unwinds and UNZIPS, so the two strands separate
  2. RNA Nucleotides line up along the template strand, according to the COMPLEMENTARY base pairs
  3. The RNA Nucleotides link up one at a time to form an mRNA Molecule (how? Bonds form between the ribose and phosphate groups. Together, they make the sugar phosphate the backbone of the molecule)
  4. When it has been transcribed, the mRNA Molecule leaves the Nucleus through pores in the nuclear membrane and enters the Cytoplasm

  
• In TransLATION:

  1. The mRNA attaches to a Ribosome
  2. tRNA Molecules carrying Amino Acids are brought to the Ribosome, where each anticodon is complementary to a particular codon in mRNA. There is a SPECIFIC tRNA Molecule for every type of Amino Acid
  3. Each tRNA Molecule binds to its complementary codon in mRNA, forming bonds between one Amino Acid and the next one, forming a chain. This growing chain is called a Polypeptide

  At the end of the chain, a 'stop codon' tells the 'translation machinery' that the protein is finished, and then it's released

  A) tRNA