How are oxygen and carbon dioxide carried into the blood?

Answer 1

Oxygen is carried in blood in 2 forms:

1) Dissolved in plasma. (Normally insignificant).

2) Bound to hemoglobin in red blood cells.

Carbon dioxide is carried by the red blood cell in three forms. They are as follows:

1) Dissolved CO2: CO2 can cross the red cell membrane and dissolve in RBC water.

2) Carbamino compounds: Approximately 30% of RBC contents is hemoglobin. CO2 can form carbamino hemoglobin on amine groups. The H+ released by this reaction is buffered by histidine residues (imidazole group) on the hemoglobin itself.

3) Bicarbonate: Carbonic anhydrase is present in RBCs and catalyze the formation of carbonic acid which dissociated to hydrogen ion and bicarbonate. The H+ is buffered by hemoglobin.

Answer 2

CO2 is carried in blood in three different ways. (The exact percentages vary depending whether it is arterial or venous blood.)

Most of it (about 80% – 90%) is converted to bicarbonate ions HCO3− by the enzyme carbonic anhydrase in the red blood cells.[citation needed]
5% – 10% is dissolved in the plasma[citation needed]
5% – 10% is bound to hemoglobin as carbamino compounds.[citation needed]
The CO2 bound to hemoglobin does not bind to the same site as oxygen; rather it combines with the N-terminal groups on the four globin chains. However, because of allosteric effects on the hemoglobin molecule, the binding of CO2 does decrease the amount of oxygen that is bound for a given partial pressure of oxygen.

Hemoglobin, the main oxygen-carrying molecule in red blood cells, can carry both oxygen and carbon dioxide, although in quite different ways. The decreased binding to carbon dioxide in the blood due to increased oxygen levels is known as the Haldane Effect, and is important in the transport of carbon dioxide from the tissues to the lungs. Conversely, a rise in the partial pressure of CO2 or a lower pH will cause offloading of oxygen from hemoglobin. This is known as the Bohr Effect.

Carbon dioxide may be one of the mediators of local autoregulation of blood supply. If it is high, the capillaries expand to allow a greater blood flow to that tissue.[citation needed]

Bicarbonate ions are crucial for regulating blood pH. As breathing rate influences the level of CO2 in blood, too slow or shallow breathing causes respiratory acidosis, while too rapid

Answer 3

Hi. In solution. And attached to hemoglobin.