No single organelle is responsible for this entire process. The mitochondria breaks down the food and releases energy molecules in the form of ATP. Then, when the body requires energy, enzymes break down ATP to ADP molecules and release the chemical energy stored in phosphate bond. In the presence of oxygen, one molecule of glucose will release as much as 30 ATP molecules. In comparison, anaerobic respiration generates only about 2 ATP molecules per molecule of glucose. These ATP molecules are broken down by enzymes known as ATPase, which break down one of the three phosphate bonds, releasing energy in the process and results in formation of ADP molecules.
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