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Protein Structure

Two groups
1. Globular Proteins
  1. Take part in reactions
  2. Enzymes
  3. Roughly spherical
2. Fibrous Proteins
  1. Have structural roles
    1. Such as giving strength or elasticity
  2. E.g. Collagen and keratin
Made up of amino acids
1. Join together in a condensation reaction
  1. Chain of amino acids is called a polypeptide
    1. Proteins consist of one or more polypeptide
  3. 2 amino acids form a dipeptide
2. 20 different amino acids
  1. Join together in any order
    1. Infinite number of different protein molecules
Contain carbon, hydrogen, oxygen and nitrogen. They often contain sulfur and phosphorus
Four levels
1. Primary Structure
  1. The sequence of amino acids in the polypeptide
2. Secondary Structure
  1. The twisting and folding of the polypeptide chain to form an alpha helix or beta pleated sheet, held together by hydrogen bonds
3. Tertiary Structure
  1. The complex twisting and folding of the polypeptide chain to give a 3 dimensional shape. Held together by bonds between the R groups
    1. Hydrogen bonds, ionic bonds, covalent bonds, disulfide bonds
4. Quaternary Structure
  1. The presence of more than one polypeptide chain in a protein. The polypeptide chain are held together by bonds between R groups AND/OR the presence of non-protein prosthetic groups in the working protein

Protein Structure

	Created by abbiebubble over 10 years ago