Reactome: A Curated Pathway Database

Reversible hydration of carbon dioxide (R-HSA-1475029)

Species Homo sapiens


Carbonic anhydrases reversibly catalyze the hydration of carbon dioxide and directly produce bicarbonate and protons, bypassing the formation of carbonic acid (reviewed in Lindskog 1997, Breton 2001, Esbaugh and Tufts 2006, Boron 2010, Gilmour 2010). Carbonic anhydrase deprotonates water to yield a zinc-hydroxyl group and a proton which is transferred to external buffer molecules via histidine or glutamate residues in carbonic anhydrase. The hydroxyl group reacts with carbon dioxide in the active site to yield bicarbonate. A water molecule displaces the bicarbonate and the reaction cycle begins again. There are currently 12 known active carbonic anhydrases in humans.

Locations in the PathwayBrowser
Additional Information
Compartment cytosol , extracellular region , mitochondrial matrix , plasma membrane
GO Biological Process bicarbonate transport (0015701)
Literature References
pubMedId Title Journal Year
19879980 Evaluating the role of carbonic anhydrases in the transport of HCO3--related species Biochim Biophys Acta 2010
20541618 Perspectives on carbonic anhydrase Comp Biochem Physiol A Mol Integr Physiol 2010
9336012 Structure and mechanism of carbonic anhydrase Pharmacol Ther 1997
11875253 The cellular physiology of carbonic anhydrases JOP 2001
16679072 The structure and function of carbonic anhydrase isozymes in the respiratory system of vertebrates Respir Physiol Neurobiol 2006