protein structure

primary structure:

• sequence of amino acids in the polypeptide chain.

secondary structure:

• protien folding.
• held together by hydrogen bonds.

the a helix: wound round to form a helix, held together by hydrogen bonds.
the b sheet: zig zags back and forth forming a sheet, held together by hydrogen bonds.

tertiary structure:

• compact globular sturcture.
• formed by the folding up of a whole polypeptide chain.
• held togehter by bonds between the R groups.

quaternary structure:

• arrangement of the different chains.