NEET BIOLOGY

Detailed explanation-1: -If the denatured protein is suddenly placed in a refolding solution without denaturant and in an oxidizing environment (such as oxidized glutathione), the reduced cysteine side chains could start forming disulfide pairs, but only one combination of such pairs would be native.

Detailed explanation-2: -Proteins can be unfolded either chemically by denaturing agents (such as urea) or by mechanical force (such as optical tweezers). If these two methods produce quite different unfolded structures, the course of the subsequent protein refolding when these agents are removed will be quite different.

Detailed explanation-3: -During protein unfolding, the force exerted by the cantilever is transmitted along the backbone into the membrane protein. The latter is stabilized in its conformation by the interplay between local forces, which in their complexity are represented by the potential energy landscape.

Detailed explanation-4: -During the denaturation of proteins, the secondary and tertiary structures get destroyed and only the primary structure is retained. Covalent bonds are broken and interaction between amino-acid chains gets disrupted. This results in the loss of biological activity of the proteins.

Detailed explanation-5: -Denaturation involves the breaking of many of the weak linkages, or bonds (e.g., hydrogen bonds), within a protein molecule that are responsible for the highly ordered structure of the protein in its natural (native) state. Denatured proteins have a looser, more random structure; most are insoluble.