random coil

This term is primarily used in polymer chemistry and biochemistry to describe a state of maximum entropy. It characterizes a chain that lacks a stable, folded architecture, such as an alpha-helix or beta-sheet, and instead behaves like a flexible string moving randomly in a solvent.

In a biological context, the random coil state is often associated with denatured proteins. When a protein loses its native three-dimensional shape due to heat or chemical agents, it transitions from a highly ordered structure into a random coil, rendering it biologically inactive.