Basically, it's your bodies way of breaking own food molecules to save as energy for later. Cellular Respiration takes oxygen and glucose, and converts it to carbon dioxide, water, and energy for us to use. Energy is released in the form of ATP.
The first step in Cellular Respiration is called Glycolysis. The second is the Krebs Cycle and the third and final step is called the Electron Transport Chain.
Glycolysis is an anaerobic process that occurs in the cytoplasm. During Glycolysis, glucose is being broken down and ATP is being produced in small amounts.
The Krebs Cycle is an aerobic process that takes place in the mitochondria. During the Cycle, acids produced from Glycolysis are broken down, producing energy carriers. These carriers are moved into the final stage of Cellular Respiration.
The Electron Transport Chain is also an aerobic process that takes place in the mitochondria. In the ETC, electron carriers release stored energy to produce ATP.