STRUCTURE OF PROTEINS

Proteins which are mixed polymers of amino acids can have up to four structural levels - Primary, Secondary, Tertiary, Quaternary

1.       PRIMARY STRUCTURE (1o Structure)

1. Newly synthesized protein is called 1º protein.
2. It is the straight chain protein.
3. In these only peptides bonds are present.
4. Most unstable protein.
5. Initially all protein are primary proteins.
6. The distance between two adjacent peptide bonds is about 0.35 nm.
7. Primary structure does not give any information about the functional properties of the protein.

2.       SECONDARY STRUCTURE (2o Structure).

1. Helically coiled protein
2. In this hydrogen bonds are also present along with peptide bonds
3. Secondary structure is of three types -  a -helix,  b -pleated, Collagen helix