- digestion ( trypsin, pepsin, amylase)

- metabolism

- oxygen transport

- fatty acids transport

- iron storage

- skin and bone (collagen)

- elastic ligaments (elastin)

- antibodys

- muscle contractions (actin and myosin)

- blood glucose regulation ( insulin and glycogen)

- Carbon

- hydrogen

- oxygen

- Nitrogen

- and sometimes sulphur

- a hydrogen atom

- a carboxyl (COOH) group

- An amino (NH2) group

- a unique R group or side chain

- an amino functional group

- a carboxyl functional group

- non-polar

- polar

- some amino acids have charged R groups

- leads to the formation of a chain of aminoacids called a peptide bond

- forms a peptide bond

- condensation reaction

- the sequence of amino acids in the polypeptidechain

- each amino acid is linked by peptide bonds

- disulphide bridges are also part of the primarystructure

- the areas of finding or coiling within a protien

- amino acids interact non-covalently (hydrogenbonding) between the amino acid side chains

- hydrogen bonding coils the polypeptide into astabilised secondry structure

- alpha helices

- beta pleated sheets

- the final 3D shape of a protein

- the function of a protein depends on thetertiary structure

- the forces which give rise to and stabilise thetertiary structure are

- involves the clustering of several individualpolypeptide chains into a final and precise 3Dshape

- stabilisation of tertiary structure

- elongated molecules whose secondarystructure is the dominant structural feature

- insoluble in water and physically tough

- provide mechanical support to cells and toentire organisms

- polypeptide chains form a single repetitivestructure which is twisted regularly andarranged in bundles or sheets

- are relatively sepherical