universal code

• what are the three features the genetic code?

  is is degenerate, universal and non-overlapping
• at the start of every gene the start codon codes for an amino acid called methionine which is later removed if it is not needed for the structure which initiates translation
• at the end of every gene, the last three bases called the stop codon dont code for amino acids as they mark the end of the chain and detached off the ribosome and stops translation
• degenerate

  • each amino acid is coded for by more than one base
  • this is an advantage as if a mutation occurs it still might code for the same amino acid
• universal

  • the same triplet of bases codes for the same amino acid in every organism
  • the advantage is that it makes genetic engineering possible
• non-overlapping

  • each base in a gene is only part of one triplet base that codes for one amino acid therefore each codon is read as a discrete unit
  • the advantage is that if there is a mutation it will only effect one codon therefore one amino acid
• introns are sections of dna that dont code for amino acids, they are only in eukaryotic dna
• extrons are part of dna that code for amino acids
• genome is an organisms complete set of dna in one cell
• the genome should never change, whereas the proteome of the cell is constantly changing depending on which protein is currently needed
• whereas a proteome is the full range of proteins in one cell
• exons are a triplet of bases that code for a sequence of amino acids