We breathe oxygen that is captured through cellular respiration.
Explanation:
Cellular respiration is the chemical process carried out by living beings and takes place inside cells. It is necessary to maintain the functioning of our body. For cellular respiration to happen efficiently, in addition to the absorption of oxygen (which is essential for our breathing), the body's nutritional needs must be met. That is, living beings need to ingest carbohydrates, lipids and proteins. However, as these molecules are large, the organism needs to break them down so that they can be used as an energy source. After ingestion, simple carbohydrates, such as glucose, fatty acids and amino acids, remain. Cellular respiration takes place at this stage.
Most used by living beings, aerobic respiration uses glucose as its main source of energy. Its function is to start from the molecules, obtained by the producing organisms, in the process of photosynthesis and by consumers' food. Aerobic respiration is represented by the following equation: C6H12O6 + 6 O2 - 6 CO2 + 6 H2O + Energy
In this equation, it is possible to identify that the glucose molecule (C6H12O6) is divided, so that it can originate the simplest substances (CO2 and H2O). This mechanism occurs within the mitochondria, a cytoplasmic organelle that acts as a power plant. With this, several reactions with the participation of enzymes and coezimas are carried out within the aerobic respiration, which favors the constant oxidation of glucose. In this way, this way of obtaining energy generates thirty-six moles of ATP from one mole of glucose. Aerobic respiration is divided into three stages: glycolysis, the Krebs cycle and oxidative phosphorylation (respiratory chain).
