Primary, secondary, tertiary and quaternary structureप्राथमिक, द्वितीयक, तृतीयक और चतुष्क संरचनाPrimary, secondary, tertiary and quaternary structure

NCERT Fig 10.3, 10.4 · Class 12 Chemistry · Chapter 10 · interactive diagram

Parts and what they mean

• Primary structure (प्राथमिक संरचना) — The specific sequence of amino acids in each polypeptide chain. Any change in the sequence creates a different protein.
• Secondary structure (द्वितीयक संरचना) — The shape of the long chain: α-helix or β-pleated sheet, from regular folding of the backbone by hydrogen bonds between >C=O and –NH– of peptide bonds.
• Tertiary structure (तृतीयक संरचना) — Overall folding of the chain (further folding of the secondary structure) → fibrous or globular shape. 2° and 3° are stabilised by hydrogen bonds, disulphide linkages, van der Waals and electrostatic forces.
• Quaternary structure (चतुष्क संरचना) — Proteins made of two or more polypeptide chains (sub-units): the spatial arrangement of these sub-units. Haemoglobin has four (two of one type, two of another).

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 10.3, 10.4. Report a mistake