Where does coagulation occur in a souffle?

Coagulation in a soufflé primarily occurs in the egg proteins, specifically the albumin in egg whites and the proteins in the yolks. When the soufflé is baked, the heat causes these proteins to denature and then coagulate, creating a stable structure that supports the soufflé's rise. This process is crucial for achieving the light, airy texture characteristic of a well-made soufflé.