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