The primary fuel source for mitochondrial energy production is glucose. Mitochondria, often referred to as the "powerhouses" of the cell, utilize glucose through a series of biochemical pathways known as cellular respiration. This process involves glycolysis, the citric acid cycle, and the electron transport chain, culminating in the production of ATP. Efficient energy production is critical for various cellular functions, and the breakdown of glucose allows cells to generate the necessary energy to sustain life.