Which of the following correctly describes mechanisms of CO transport?
• 20% of CO2 is dissolved directly into the plasma.
• Carbonic anhydrase converts 02 to CO2.
Carbonic anhydrase is responsible for bonding CO2 to hemoglobin.
• The chloride shift mechanism enhances CO2 transport.
• 7-8% of CO2 is carried in the form of carbaminohemoglobin.
• The chloride shift mechanism enhances CO2 transport.
• 7-8% of CO2 is carried in the form of carbaminohemoglobin.
The correct statements describing mechanisms of CO transport are:
• Carbonic anhydrase converts CO2 to carbonic acid, which then dissociates into bicarbonate ions and hydrogen ions. This process helps transport CO2 from tissues to the lungs.
• The chloride shift mechanism enhances CO2 transport. In this mechanism, chloride ions move into erythrocytes (red blood cells) as bicarbonate ions move out. This helps maintain the electrochemical balance and facilitates CO2 transport.
• 7-8% of CO2 is carried in the form of carbaminohemoglobin. CO2 can bind to amino groups on the hemoglobin protein, forming a compound called carbaminohemoglobin. This allows for additional CO2 transport in the blood.
The statement "20% of CO2 is dissolved directly into the plasma" is incorrect. Only a small portion of CO2 (around 5%) is dissolved directly into the plasma.
The statement "Carbonic anhydrase is responsible for bonding CO2 to hemoglobin" is also incorrect. Carbonic anhydrase is responsible for the conversion of CO2 to carbonic acid, but it does not directly bond CO2 to hemoglobin. CO2 primarily binds to hemoglobin via the carbaminohemoglobin mechanism mentioned earlier.