Oxygen TransportGeneral Cell Metabolism Cell metabolism is based on the same general principle as the combustion of any fuel, whether it be in the automobile, power plant, or a home furnace. The general combustion reaction is:
CH2O (fuel) + O2 ===> CO2 + HOH
the same reaction occurs in the cells. The "fuel" comes from food in the form of carbohydrates, fats, and proteins.The important principle to remember is that oxygen is needed by the cell and that carbon dioxide is produced as a waste product of the cell.
Carbon dioxide must be expelled from the cells and the body.The lungs serve to exchange the two gases in the blood. Oxygen enters the blood from the lungs and carbon dioxide is expelled out of the blood into the lungs. The blood serves to transport both gases. Oxygen is carried to the cells. Carbon dioxide is carried away from the cells.