Mitochondrial proteins are essential components found within the mitochondria, the energy-producing organelles in cells. These proteins play crucial roles in various cellular processes, including energy production through cellular respiration, metabolism, and the regulation of apoptosis, or programmed cell death. Most mitochondrial proteins are encoded by nuclear DNA and are imported into the mitochondria after being synthesized in the cytoplasm. Some proteins are encoded by the mitochondrial DNA, which is inherited maternally. Proper functioning of these proteins is vital for maintaining cellular health and energy balance.