Cellular respiration is the process by which cells convert glucose into ATP, their main source of energy.

During cellular respiration, glucose is broken down into carbon dioxide and water in a series of chemical reactions. This process occurs in three stages: glycolysis, the Krebs cycle, and oxidative phosphorylation.

Glycolysis takes place in the cytoplasm and involves the breakdown of glucose into two pyruvate molecules. This process generates a small amount of ATP and NADH, which is a molecule that carries electrons to the next stage of cellular respiration.

The Krebs cycle, also known as the citric acid cycle, takes place in the mitochondria and involves the breakdown of pyruvate into carbon dioxide. This process generates more ATP and NADH.

Oxidative phosphorylation takes place in the inner membrane of the mitochondria and involves the transfer of electrons from NADH to a series of electron carriers. This process generates a large amount of ATP through a process called chemiosmosis.

Overall, cellular respiration generates ATP by breaking down glucose into smaller molecules and using the energy released to power the production of ATP. This process is essential for the survival of cells and allows them to carry out all of their necessary functions.