Protein structure

• Amino acid


  . NH2-CHR-COOH

  . NH2 Amine group

  . COOH Carboxylic group
• Primary structure(1)


  . Polymers of the the amino acid monomer

  . Condensation reaction forms 'peptide' bond

  . NH3-CHR-COOH + NH3-CHR-COOH -> NH3-CHR-CO-NH-CHR-COOH + H20

  The name of the peptide depends on how many amino acids there are, 2 amino acids = Di peptide chain 
• Secondary structure(2)


  . A long sequence of amino acids causes it to bend into 'Alpha helix' or 'Beta pleated sheets'

  . Held together by Hydrogen bonds formed from C=O and one H
• Tertiary structure (3)

  . Unique 3D structure

  . Ionic + Hydrogen bonds and disulphide bridges

  . Must contain sulfur in the amino acid's R group to form disulphide bridges (S---S)
• Quarternary structure(4)


  . A protein made up of multiple polypeptide chains

  . Haemoglobin is mad euo of 4 poly peptide chains