* CO2 Production: Cells produce CO2 as a byproduct of cellular respiration, the process that generates energy (ATP).
* Concentration Gradient: The concentration of CO2 inside the cell is higher than the concentration outside the cell. This difference creates a concentration gradient.
* Diffusion: CO2 naturally moves from areas of high concentration to areas of low concentration. This movement, driven by the concentration gradient, is called diffusion.
* Cell Membrane: CO2 is a small, nonpolar molecule. This allows it to easily pass through the cell membrane's phospholipid bilayer without requiring any special transport proteins.
* Bloodstream: Once CO2 leaves the cell, it diffuses into the surrounding interstitial fluid and then into the bloodstream. The bloodstream carries it to the lungs, where it is exhaled.
Note: While diffusion is the primary mechanism for CO2 transport, in some cases, a protein called carbonic anhydrase can help facilitate the movement of CO2 across cell membranes by converting it to bicarbonate ions (HCO3-).
