What is the maximum ATP production in eukaryotes via respiration?

The maximum ATP production in eukaryotes during cellular respiration is generally considered to be 36 ATP molecules per glucose molecule. This total is reached through the combined processes of glycolysis, the Krebs cycle, and the electron transport chain.

In glycolysis, which occurs in the cytoplasm, 2 ATP molecules are produced via substrate-level phosphorylation. During the Krebs cycle, which takes place in the mitochondrial matrix, an additional 2 ATP molecules are generated. However, most of the ATP is generated in the electron transport chain, located in the inner mitochondrial membrane, where electron carriers like NADH and FADH2 are oxidized.

The NADH produced during glycolysis and the Krebs cycle contributes significantly to ATP production in the electron transport chain. Each NADH can yield approximately 2.5 ATP, and each FADH2 can yield about 1.5 ATP through oxidative phosphorylation. When calculating the total ATP yield from one glucose molecule, the contributions from NADH and FADH2 during these processes lead to a sum that reaches 36 ATP under ideal conditions for eukaryotic cells.

While some texts might mention yields of 38 ATP under certain conditions, these figures are often applicable to prokaryotic cells or theoretical maximal