Genes

• What is a gene?

  A gene is a section of DNA which codes for a specific protein resulting in characteristics
• gene to protein


  Transcription- converts the DNA gene sequence into mRNA that can leave the nucleus

  Translation- converting mRNA into amino acid sequences which form to make a protein

  
• the genetic code 


  1)the genetic code is degenerate

  2)the genetic code is non overlapping

  3)the genetic code is universal
• The genetic code is degenerate 


  degenerate- there is more than one codon per amino acid

  -there are 64 different codons but only 20 amino acids
• The genetic code is non overlapping


  The codons of 3 nitrogenous bases are read distinctly from each other
• The genetic code is universal 


  every living species uses the same four nitrogenous bases meaning it will use the codons therefore using the same amino acids
• What is replaced in mRNA during transcription?


  'T' is replaced with 'U'
• What is the start codon in protein synthesis?


  AUG
• What amino acid does the start codon AUG code for?


  Met (Methionine)
• What are the stop codons in protein synthesis?


  UAA, UAG, UGA
• Why is Met significant in protein synthesis?


  Met is at the start of every protein.
• What is the role of codons in mRNA?

  • Codons are sequences of three nucleotides.
  • Each codon corresponds to a specific amino acid or a stop signal.
  • They dictate the sequence of amino acids in a protein.
• What amino acid does the codon AUG code for?


  Met
• What is the significance of peptide bonds?


  They link amino acids together in proteins
• What are peptide bonds and dipeptides?


  • Peptide bonds: Link amino acids together
  • Dipeptides: Composed of two amino acids linked by a peptide bond
• Peptide bonds and dipeptides


  Diagram of the formation of a dipeptide

  
• mRNA sequences


  Is this diagram we can see that during mRNA transcription changing the T to a U