What is the primary function of mitochondria in a cell?

Mitochondria are often referred to as the "powerhouses" of the cell due to their crucial role in cellular respiration, a process that converts biochemical energy from nutrients into adenosine triphosphate (ATP), the energy currency of the cell. During cellular respiration, glucose and oxygen are utilized to produce ATP, with carbon dioxide and water generated as byproducts.

This process involves multiple stages, including glycolysis, the Krebs cycle, and the electron transport chain, all of which occur within or across mitochondrial membranes. The inner mitochondrial membrane houses the proteins and complexes essential for the electron transport chain and ATP synthesis.

Other processes mentioned in the options play essential roles in cellular function but do not take place within mitochondria. Photosynthesis occurs in chloroplasts, proteins are synthesized in ribosomes, and genetic material is stored in the nucleus. Mitochondria are specialized organelles that uniquely facilitate energy production, which is vital for maintaining the functions and activities of eukaryotic cells.