The extra carbon (C) in the carbon dioxide (CO2) that we exhale comes from the carbon-containing compounds in our bodies, particularly glucose (C6H12O6). When we consume food, our bodies break down glucose through a process called cellular respiration, which occurs in our cells to produce energy.
During cellular respiration, glucose reacts with oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy in the form of adenosine triphosphate (ATP). The simplified equation for cellular respiration is:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (ATP)
As a result of this metabolic process, carbon dioxide is generated as a waste product. The carbon atoms from glucose are combined with oxygen to form carbon dioxide, which is then transported via the bloodstream to the lungs, where it is exhaled when we breathe out.
It's important to note that while we exhale carbon dioxide, our bodies are constantly producing carbon dioxide as a byproduct of cellular respiration. This continuous exchange of oxygen and carbon dioxide is part of the respiratory process, allowing our bodies to obtain the oxygen needed for cellular respiration and eliminate carbon dioxide waste.