What is required to form a holoenzyme?

To form a holoenzyme, it is essential to combine an apoenzyme with a cofactor. A holoenzyme is the active form of an enzyme that includes its non-protein component, which can be a cofactor or a coenzyme. Cofactors can be metal ions or organic molecules, and they are crucial for the enzyme's activity, as they help the enzyme achieve its functional form.

The apoenzyme is the protein part of the enzyme that, on its own, is inactive. When it binds to the necessary cofactor, the resulting holoenzyme is capable of catalyzing its specific biochemical reaction.

While prosthetic groups, which are tightly bound cofactors, can also contribute to the structure of some holoenzymes, the more general requirement for holoenzyme formation is the combination of an apoenzyme and a cofactor. This distinction is key in understanding enzyme structure and function, as the holoenzyme represents the fully active and functional enzyme complex.