Mitochondrial metabolism is central to cellular energy conversion, involving processes such as the TCA cycle, oxidative phosphorylation, and β-oxidation. Mitochondria are widely distributed in the cytoplasm of cells and have a double membrane structure, containing mtDNA. They participate in multiple signaling pathways including ATP production, calcium ion regulation, and apoptosis. Mitochondrial function relies on proteins encoded by both nuclear genes and mtDNA, and specific expression is crucial for cellular metabolic status. Mutations in mtDNA or abnormalities in nuclear gene regulation are associated with various genetic diseases, neurodegenerative disorders, and tumors. Cells maintain mitochondrial function through a dynamic balance of mitochondrial biogenesis and autophagy.