Cellular respiration occurs in the mitochondria, which are organelles found in eukaryotic cells. The mitochondria are often referred to as the “powerhouse” of the cell because they are responsible for producing most of the ATP needed for cellular processes.
The process of cellular respiration occurs in several stages, each of which takes place in a different part of the mitochondria. The first stage, glycolysis, occurs in the cytoplasm outside of the mitochondria, but the pyruvate molecules produced by glycolysis are transported into the mitochondria for the next stages of respiration.
The second stage of cellular respiration, the citric acid cycle, takes place in the mitochondrial matrix, which is the fluid-filled space inside the mitochondria. This stage involves a series of chemical reactions that break down the pyruvate molecules into carbon dioxide and energy-rich molecules such as NADH and FADH2.
The third and final stage of cellular respiration, oxidative phosphorylation, takes place in the inner membrane of the mitochondria. This stage involves the transfer of electrons from NADH and FADH2 to oxygen through a series of electron transport chain reactions, which generates a proton gradient that is used to produce ATP through a process called chemiosmosis.
In summary, cellular respiration occurs in the mitochondria, with each stage of the process taking place in a different part of the organelle. The mitochondria are essential for the production of ATP, which is required for many cellular processes and is the primary source of energy for most living organisms.
Read more about Cellular Respiration here: