Carbon Dioxide reacts with water in blood plasma to form carbonic acid.Suppose that you are a molecule of carbon dioxide. Describe the chemical reactions that take place when you enter the blood and when you leave the blood. Explain what determines how these reactions occur. Be sure to include all terms from the chapter that are related to the chemical reaction (dont need to include terms)
As a molecule of carbon dioxide (CO2), when you enter the blood, you undergo a series of chemical reactions. One of these reactions involves the reaction of carbon dioxide with water (H2O) in blood plasma to form carbonic acid (H2CO3). The chemical equation for this reaction is as follows:
CO2 + H2O ⇌ H2CO3
This reaction is catalyzed by an enzyme called carbonic anhydrase, which is abundantly present in red blood cells. Carbonic anhydrase speeds up the reaction, allowing it to occur more efficiently.
When carbon dioxide leaves the blood, it reverses the reaction by dissociating from carbonic acid back into its gaseous form. This process is facilitated by the same enzyme, carbonic anhydrase but in a reverse direction. The chemical equation for the reverse reaction is:
H2CO3 ⇌ CO2 + H2O
The direction of these reactions is determined by the concentration of reactants and products. According to Le Chatelier's principle, a principle in chemistry, when there is an excess of carbon dioxide, the equilibrium shifts towards the formation of carbonic acid. Conversely, when there is an excess of carbonic acid, the equilibrium shifts towards the formation of carbon dioxide.
In the blood, the concentration of carbon dioxide is relatively high due to its release from body tissues as a waste product of cellular respiration. This high concentration of CO2 drives the reaction towards the formation of carbonic acid. On the other hand, when carbon dioxide is transported to the lungs, where the concentration of CO2 decreases, the equilibrium shifts towards the dissociation of carbonic acid to produce carbon dioxide and water.
It is important to note that these reactions occur rapidly and continuously in the blood to maintain a delicate balance of pH levels. The formation of carbonic acid helps in regulating the pH of the blood, as it can dissociate to release protons (H+) and bicarbonate ions (HCO3-), which act as buffers to maintain the blood's acidity within a narrow range.