Let's read the chemical equation for cellular respiration. The equation shows that cells use<span> six molecules of </span>oxygen<span> (6O</span>2<span>) to </span>break down<span> one molecule of </span>glucose(C6H12O6<span>). The arrow shows that when the sugar is broken </span>down<span> something else is produced. Energy, water, and carbon dioxide are produced.</span>