What is the primary function of mitochondria?

The primary function of mitochondria is ATP production, which is essential for providing energy to the cell. Mitochondria are often referred to as the "powerhouses" of the cell because they convert the energy stored in food molecules into adenosine triphosphate (ATP) through the process of cellular respiration. This process involves multiple steps, including glycolysis, the citric acid cycle, and oxidative phosphorylation, which occur in various parts of the mitochondria.

ATP serves as the energy currency of the cell, powering a multitude of cellular processes, such as muscle contractions, active transport across cell membranes, and biochemical reactions necessary for cellular maintenance and function. Without sufficient ATP, cells would be unable to perform vital functions, leading to impaired health and function.

The other choices refer to processes that occur in different cellular components. Photosynthesis is a process that takes place in chloroplasts found in plant cells, protein synthesis occurs at the ribosomes, and cellular repair involves multiple cellular mechanisms that do not specifically designate a single organelle like mitochondria.