Question

Many biological molecules have several possible tertiary structures (aka states or shapes) with different free energies. The lowest-free-energy one is always the most probable (and therefore the most common) shape, but a higher-free-energy state may be present as well. Though the higher- energy state may occur infrequently, it can be important biologically; for instance, the low energy state may be inert, while the high-energy shape catalyzes a reaction.

Let's call the normal (the ground state) shape of a molecule α (alpha) and the higher-energy state (the excited state) β (beta). These two states have free energies Gα and Gβ. When the molecule is floating in a thermal bath of temperature T, the probability that the molecule is in state α is Pα and that it is in state β is Pβ.

Question: Sketch Pα and Pβ over a large range of temperatures (0.01 ΔG / kB < T < 100 ΔG / kB).

Answer 1