Change in Pco

Figure 8. Results of a geochemical model investigating the effects of pH buffering by acetic acid-acetate on the response of the carbonate system to changes in pCO. Increases in the pC02 of calcite-saturated solutions will promote calcite undersaturation for initial concentrations of acetic acid up to approximately 0.06 m (3600 mg/I). This is called the crossover concentration. (Reproduced with permission from Ref. 7. Copyright 1989 Elsevier).

Figure 8. Change in pco with time after mixing equal volumes of suspension A (pC02 w and solution B (pC02 70 torr) (41)...

Carbon dioxide (CO ) is produced by the body s metabohsm at approximately the same rate as consumption, about 3 mL/kg/minute at rest, increasing dramaticahy with heavy exercise. CO diffuses readily from the ceUs into the bloodstream, where it is carried partly as bicarbonate ion (HCO3 ), partly in chemical combination with hemoglobin and plasma proteins, and partly in soln-tion at a partial pressnre of 6 kPa (46 mm Hg) in mixed venons blood. CO is transported to the lung, where it is normaUy exhaled at the same rate at which it is produced, leaving a partial pressure of 5.2 kPa (40 mm Hg) in the alveoh and in arterial blood. An increase in Pco results in a respiratory acidosis and may be due to decreased ventilation or the inhalation of CO, whereas an increase in ventilation results in decreased Pco and a respiratory alkalosis. Since CO is freely diffusible, changes in blood Pco and pH soon are reflected by intraceUular changes in Pco and pH. 

The pressure of CO2 at equilibrium, Pco2(eq). is the initial pressure, Pcojtmit). niinus X, the CO2 that reacts (the change in Pco, due to the reaction) ... 

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