What are the two stages of aerobic respiration?

The two stages of aerobic respiration are indeed the Krebs cycle and the electron transport chain. Aerobic respiration begins with glycolysis, which occurs in the cytoplasm and breaks down glucose to produce pyruvate, but this process is not considered one of the main two stages focused on in the context of aerobic respiration.

After glycolysis, the pyruvate moves into the mitochondria where it enters the Krebs cycle (also known as the citric acid cycle). During this cycle, the pyruvate is further broken down, releasing carbon dioxide and transferring high-energy electrons to electron carriers such as NADH and FADH2. The Krebs cycle plays a crucial role in generating these energy-rich electron carriers.

Following the Krebs cycle, the electron transport chain takes place across the inner mitochondrial membrane. The high-energy electrons carried by NADH and FADH2 are passed along a series of proteins in this chain. The energy released during this process is used to pump protons across the membrane, creating a gradient. Finally, protons flow back through ATP synthase, leading to the production of ATP, which is the primary energy currency of the cell.

Thus, the combination of the Krebs cycle and the electron transport chain represents the core stages of aerobic respiration where