The Schellman helix-coil model. A helix-coil model developed by JA Schellman [7] is simpler than the Zimm- Bragg model, and works well for short chains. Consider a chain having N units. Write an expression for 2k, the number of configu- rations of a chain that has all its H units in a single helix k units long, as a function of N and k.
