SDS, an anionic detergent, plays a dual role in protein electrophoresis. It denatures proteins by breaking non-covalent interactions, thus unfolding them into linear chains. It also coats proteins with a uniform negative charge proportional to their size, ensuring that the separation during SDS-PAGE is based solely on molecular weight rather than shape or charge.
| List I (Enzyme) | List II (Function) |
|---|---|
| (A) Cytochrome oxidase | (I) Electron transport system |
| (B) Topoisomerases | (II) Change linking number |
| (C) Cohesins | (III) DNA Replication |
| (D) PCNA | (IV) Cell cycle |