When a person breathes the lungs absorb oxygen which is used by cells to carry out process of what?

When a person breathes, the lungs absorb oxygen which is used by cells to carry out the process of cellular respiration. Cellular respiration is a set of metabolic reactions that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. This process is essential for the survival of all living organisms because ATP serves as the main energy currency for cells.

During cellular respiration, oxygen is utilized as the final electron acceptor in the electron transport chain, which is a series of protein complexes located in the inner mitochondrial membrane. As electrons pass through these complexes, their energy is used to pump protons across the membrane, creating a proton gradient. This gradient drives the synthesis of ATP through a process called oxidative phosphorylation.

The overall chemical equation for cellular respiration is:

C6H12O6 (glucose) + 6O2 (oxygen) → 6CO2 (carbon dioxide) + 6H2O (water) + energy (as ATP)

Additionally, during cellular respiration, other nutrients such as carbohydrates, fats, and proteins can also be broken down and used as energy sources. However, the basic process of utilizing oxygen to generate ATP remains the same.