protein synthesis

• DNA

  Double-stranded polymer of molecules called nucleotides
• Nucleotides


  • A
  • T
  • G
  • C
• A always pairs with T on the opposite DNA strand, and C always pairs with G
• Proteins

  Polymers of amino acids
• Amino acids

  • 20 different amino acids in humans
• Order of amino acids in a protein

  Determines the shape of the protein
• Shape of a protein

  Determines its function
• Gene


  Sequence of bases that determines the order of amino acids in a protein
• Protein synthesis


  1. Transcription (in nucleus)

  2. Translation (in cytoplasm)
• Transcription

  DNA sequence is copied into a complementary template molecule called mRNA
• Translation

  mRNA attaches to a ribosome, amino acids are brought to the ribosome on tRNA molecules, ribosome reads mRNA triplets and joins amino acids in the correct order
• mRNA

  Single-stranded molecule that carries the DNA sequence information to the cytoplasm
• tRNA

  Carrier molecules that bring amino acids to the ribosome
• The protein chain folds into its unique shape after being synthesized