proteins

• GLOBULAR PROTEIN

  • mostly Soluble
  • spherical
  • ph/celsius sensitive
  • functional (transport/catalyst)
  • irregular aa
• FIBROUS PROTEIN

  • long and narrow (over 1000aa)
  • mostly insoluble
  • high tensile strength
  • structural
  • repeated aa sequences
  • not sensitive to ph/celsius change
• fibrous protein example

  • Collagen
  • triple helix
  • long
  • with h bonds
• globular protein example

  • Haemoglobin
  • small
  • 4 polypeptide chains- 2 alpha, 2 beta
  • Fe^2+ group for 02 binding
• primary structure

  • peptide bonds
  • aa sequence (specific to a protein)
• secondary structure

  • folded and held with h bonds
  • alpha helix
  • beta pleated sheet
• tertiary structure

  • h bonds
  • disulphide bonds
  • Ionic
  • further coiling between r groups
  • three dimensional
• quaternary structure

  • more than one polypeptide chain bonded
  • links between r groups
  • h bonds
  • disulphide
  • ionic