Carbonic anhydrases are a group of enzymes that catalyze the reversible reaction between carbon dioxide and water to form bicarbonate and protons. This reaction is crucial for maintaining acid-base balance in biological systems and plays a significant role in processes like respiration and photosynthesis. These enzymes are found in many organisms, including animals, plants, and bacteria. They help regulate pH levels in tissues and facilitate the transport of carbon dioxide in the bloodstream. There are several isoforms of carbonic anhydrases, each with specific functions and locations within cells.