Question

Discuss the concept of structure-function as it pertains to all 4 levels of protein organization. Nuance concerning structure equaling function at chemical and biological levels is welcome

Answer 1

Ans-  Proteins structures are made by condensation of amino acids forming peptide bonds.

Primary structure of a polypeptide is its amino acid sequenc .amino acids are connected by peptide bonds. primary structure of polypeptide determine the higher level of structural organisation.

The secondary structure is determined by the dihedral angles of the peptide bonds.

The most common types of secondary stucture are the Alpha helix and beta pleated sheet both Alpha helix and beta sheets patterns are stabilized by hydrogen bonds between the carbonyl and N- H groups in the polypeptide back bone.

Tertiary structure by the folding of proteins chains in space. The term tertiary structure refers to the unique 3D confirmation that globular protein assume as a consequence of the interaction between the side chains in their primary structure.

All information needed to hold the protein into its native tertiary structure is contained within the primary structure of the peptide chain itself.

Quaternary structure- Association of folded polypeptide molecules to complex functional proteins results in quaternary structure.Many protein like hemoglobin are composed of two or more polypeptide Chain and each polypeptide chain is called a sub unit. Subunits in a multimeric protein may be identical or quite different.