Maintaining Blood pH

Acid entering the blood stream Carbon dioxide is exhaled

HCO31- + H+ H2CO3 H2O + CO2

Bicarbonate ion circulates in the blood stream where it is in equilibrium with H+ and OH-.In the lungs, bicarbonate ions combine with a hydrogen ion and lose a water molecule to form carbon dioxide, which is exhaled.

Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 291

Alkalosis

If our breathing becomes too fast (hyperventilation)…

Carbon dioxide is removed from the blood too quickly.

This accelerates the rate of degradation of carbonic acid into carbon dioxide and water.The lower level of carbonic acid encourages the combination of hydrogen ions andbicarbonate ions to make more carbonic acid. The final result is a fall in blood H1+

levels that raises blood pH which can result in over-excitability or death.

Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 291

Acidosis

If breathing becomes too slow (hypoventilation)…

…free up acid, pH of blood drops, with associated health risks such as depressionof the central nervous system or death.

The normal pH of blood is between 7.2 – 7.4. This pH is maintained by the bicarbonate ion and other buffers.

Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 291