Explain the structure of proteins?

Proteins have four different types of structure:-

1)Primary structure - single linear chain of amino acids.

2)Secondary structure-chain of amino acids forming helix or beta pleated sheet.

3)Tertiary structure - polypeptide chain form a complex 3D structure by forming a bonding between the amino acids.

4)Quarternary structure- two or more polypeptide chains are bonded together to form this structure.