The Haldane effect refers to the effect of oxygen binding to hemoglobin molecules and its impact on the binding of carbon dioxide and other acidic gases. Synonyms for Haldane effect include the Bohr effect, the carbon dioxide effect, and the oxygenation-reduction effect. The Bohr effect is named after Christian Bohr, a Danish physiologist, who discovered that the acidity of the blood changes the affinity of hemoglobin for oxygen. The carbon dioxide effect refers to the role of carbon dioxide in reducing the oxygen-binding capacity of hemoglobin. The oxygenation-reduction effect refers to the increase in oxygen-binding capacity that occurs when oxygenated hemoglobin becomes reduced by the removal of oxygen.