metabolismsaerobic

Metabolismsaerobic, commonly called aerobic metabolism or aerobic respiration, is the cellular process of converting nutrients into usable energy (ATP) in the presence of oxygen. In eukaryotic cells, most of this energy production occurs in mitochondria, although the initial stage, glycolysis, takes place in the cytosol and can occur without oxygen. Aerobic metabolism relies on oxygen as the final electron acceptor in the electron transport chain.

The process begins when pyruvate, produced by glycolysis, is transported into mitochondria and converted to acetyl-CoA. The acetyl-CoA enters the citric acid cycle (Krebs cycle), where carbon is released as carbon dioxide and high-energy electron carriers (NADH and FADH2) are generated. The NADH and FADH2 then donate electrons to the electron transport chain, a series of protein complexes in the inner mitochondrial membrane. As electrons flow, protons are pumped across the membrane, creating a gradient that drives ATP synthase to convert ADP into ATP. Oxygen acts as the final electron acceptor, forming water after accepting electrons.

Under aerobic conditions, the complete oxidation of one glucose molecule yields approximately 30 to 32 ATP, depending on cellular shuttle systems and tissue physiology. The pathway not only supplies substantial energy but also provides intermediates for biosynthesis. Its rate is regulated by the cell’s energy state (ADP/ATP and NAD+/NADH ratios) and oxygen availability, making it central to energy-demanding tissues such as muscle and brain.