Q.1.
Structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain.
Q.2.
Structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex.
Q.3.
Structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids.