Cards (15)

  • Amino acid structure
    -4 chemical groups arranged around a central carbon atom
  • Amino acid
    -20 different amino acids that make proteins
    -R group differs for each amino acid
    -2 bonded amino acids= dipeptide
    -more than 2= polypeptide
  • Dipeptide
    Two amino acids bonded together
  • primary structure
    The specific sequence of amino acids that make up a protein
  • Secondary structure
    Coiling and pleating of parts of the polypeptide molecule
    Alpha helix and beta pleated sheets
  • Alpha helix
    -right hand coil
    -as it coils, hydrogen bonds form
    -stabilises the protein
  • Beta pleated sheets
    -Amino acid chain folds up on itself
    -hydrogen bonds form across sheets
    -stabilises the protein
  • Tertiary structure
    -overall 3D structure of a protein molecule
    -Held in place by:
    -polar interactions
    -disulphide bonds
    -Ionic interactions
    -covalent bonds
  • quatenary structure
    more than one polypeptide chain
  • Polar interactions
    -Hydrophobic R groups cluster to interior of protein molecule
    - forms hydrophobic interactions
    -stabalises protein
    -Hydrophilic R groups on outside of proteins
    - water soluable
  • Disulphide bonds/ bridges/ linkages
    -covalent bonds
    -will bond as soon as two R groups with sulphur are close
  • Ionic interactions
    -Carboxyl and amino groups form charges in solutions
    -Opposite charges come together
  • 3D proteins shapes
    -Fibrous
    -Globular
  • Fibrous
    -Structural functions
    -repetitive amino acid sequences
    -usually insoluable
  • Globular
    -metabolic functions
    -formed through hydrophobic and hydrophillic interactions
    -water soluable