What is the total number of ATP produced via aerobic cellular respiration?

The total number of ATP produced via aerobic cellular respiration is often cited as 36. This figure results from the complete oxidation of one glucose molecule through the processes of glycolysis, the citric acid cycle (Krebs cycle), and oxidative phosphorylation.

During glycolysis, which occurs in the cytoplasm, a net gain of 2 ATP molecules is produced by substrate-level phosphorylation. This process also generates 2 NADH molecules, which are later used in the electron transport chain.

In the citric acid cycle, which occurs in the mitochondria, each glucose molecule results in the production of 2 more ATP (or equivalent GTP) through substrate-level phosphorylation, along with additional NADH and FADH2. The NADH and FADH2 generated from both glycolysis and the citric acid cycle are crucial because they donate electrons to the electron transport chain, which drives ATP synthesis via oxidative phosphorylation.

The electron transport chain harnesses the energy released from electrons as they flow through the chain to pump protons across the inner mitochondrial membrane, creating a proton gradient. ATP synthase, an enzyme, utilizes this gradient to generate ATP. The total yield from NADH and FADH2 during oxidative phosphorylation contributes significantly to the overall ATP count