Cellular respiration is a metabolic process in which glucose is broken down to produce carbon dioxide and water. ATP, or biological energy, and body heat are given off in the process.
Photosynthesis is the process by which carbon dioxide and water are broken down to produce sugar and starches. Cellular respiration is the opposite process. Sugar and oxygen are delivered to the cells through the bloodstream. Cellular respiration is a process with three parts. The first stage is called glycolysis, and it takes place in the cytoplasm and the mitochondria, where the glucose is oxidized and the adenosine triphosphate, or ATP, is released. The Krebs or TCA cycle is the second stage. It occurs in the mitochondria. ATP is also produced in this process. In glycolysis, pyruvic acid is produced and is later oxidized to produce carbon dioxide and water. Water is formed during the process of the electron transfer chain.
Breathing is important to the process of cellular respiration, since breathing pulls in the oxygen that is needed for the mitochondria to synthesize sugar and to remove the carbon dioxide produced from synthesizing that sugar. Anaerobic respiration occurs without oxygen. Compared to cellular respiration, anaerobic respiration is inefficient, since only two ATPs are produced.