The powerhouse of a cell is the mitochondria, and it's responsible for generating energy through cellular respiration. However, prokaryotes do not have mitochondria.

Instead, prokaryotes have a different organelle called the plasma membrane where energy production takes place. The plasma membrane in prokaryotes is where cellular respiration, the process of breaking down glucose to produce ATP (energy), occurs.

So, while the plasma membrane is not exactly the "powerhouse" like mitochondria in eukaryotes, it is the site where energy production happens in prokaryotic cells.