What other roles do mitochondria play in living things?

In addition to being the powerhouse of the cell by producing ATP through cellular respiration, mitochondria play crucial roles in regulating metabolic processes, including the oxidation of fatty acids and the metabolism of carbohydrates. They are also involved in apoptosis, the programmed cell death, which is essential for development and tissue homeostasis. Furthermore, mitochondria contribute to the regulation of cellular calcium levels and the generation of reactive oxygen species, which play roles in cell signaling and stress responses.