Which stage of cellular respiration requires oxygen that you breathe?

The cellular respiration occurs in two main forms or mechanisms, the first one is the aerobic respiration which obviously takes place in the presence of the oxygen, O₂ molecule. While, the second takes place in the absence of the oxygen, O₂ molecules. For, the aerobic form of cellular respiration the oxygen is required to be present during the process of releasing the optimum amount of energy or executing of the whole process in a more proper way. As, the aerobic respiration is executed in the following three steps: Glycolysis. The Kreb's cycle. And the electron transport chain, to which the oxygen is mandatory or required.

Answer:in the third stage

Explanation: Aerobic respiration requires oxygen to breath in the third stage. In the third stage glucose molecule is the source of energy. Aerobic respiration occurs were cell use oxygen to convert glucose into energy. When you breath in, you breath in oxygen, when you breath out, you breath out carbon dioxide.

During cellular respiration, our body needs the oxygen we breath in, to get energy from the food we eat. cell uses oxygen to break down sugar.