Primary Structure The sequence of amino acids in the polypeptide chain



Yüklə 457 b.
tarix03.05.2018
ölçüsü457 b.
#41014





Primary Structure - The sequence of amino acids in the polypeptide chain

  • Primary Structure - The sequence of amino acids in the polypeptide chain

  • Secondary Structure - The formation of  helices and  pleated sheets due to hydrogen bonding between the peptide backbone

  • Tertiary Structure - Folding of helices and sheets influenced by R group bonding

  • Quaternary Structure - The association of more than one polypeptide into a protein complex influenced by R group bonding







The peptide backbone has areas of positive charge and negative charge

  • The peptide backbone has areas of positive charge and negative charge

  • These areas can interact with one another to form hydrogen bonds

  • The result of these hydrogen bonds are two types of structures:













Tertiary structure results from the folding of  helices and  pleated sheets

  • Tertiary structure results from the folding of  helices and  pleated sheets

  • Factors influencing tertiary structure include:

  • Hydrophobic interactions

  • Hydrogen bonding

  • Disulphide bridges

  • Ionic bonds



e.g. haemoglobin

  • e.g. haemoglobin

  • 3º structure normally folds up in a ball

  • hydrophilic R groups point outwards

  • Hydrophobic R groups point inwards

  • soluble

  • metabolic functions















Collagen is a fibrous protein made of 3 polypeptide helices held together by hydrogen bonding

  • Collagen is a fibrous protein made of 3 polypeptide helices held together by hydrogen bonding

  • Every 3rd amino acid in the chain is a glycine (very small to let the chains lie close to each other)

  • Collagen molecules are found side by side forming fbres

  • The staggered ends help to give collagen fibres great tensile strength



Quaternary structure results from the interaction of independent polypeptide chains

  • Quaternary structure results from the interaction of independent polypeptide chains

  • Factors influencing quaternary structure include:

  • Hydrophobic interactions

  • Hydrogen bonding

  • The shape and charge distribution on amino acids of associating polypeptides







Haemoglobin is a globular protein with a prosthetic ‘iron’ group

  • Haemoglobin is a globular protein with a prosthetic ‘iron’ group

  • In adults, hemoglobin is made up of 4 polypeptides (2  polypeptide chains and 2  polypeptide chains)

  • Each polypeptide surrounds a prosthetic ‘haem’ group

  • Hydrophobic interactions between side groups pointing inwards maintain the structure

  • Hydrophilic side chains point outwards making it soluble















Yüklə 457 b.

Dostları ilə paylaş:




Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©genderi.org 2024
rəhbərliyinə müraciət

    Ana səhifə