The conversion of C02 and H20 into carbonic acid during the formation of aqueous humor is catalysed by which one of the following enzymes
**Core Concept**
The formation of aqueous humor in the eye involves the conversion of carbon dioxide (CO2) and water (H2O) into carbonic acid (H2CO3), which is a crucial step in maintaining the pH balance of the eye. This process is catalyzed by an enzyme that facilitates the reversible reaction between CO2 and H2O.
**Why the Correct Answer is Right**
The enzyme responsible for catalyzing the conversion of CO2 and H2O into carbonic acid is carbonic anhydrase. This enzyme catalyzes the reversible reaction between CO2 and H2O, producing carbonic acid, which then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-). Carbonic anhydrase is present in many tissues, including the lens and ciliary epithelium of the eye, where it plays a crucial role in maintaining the pH balance of the aqueous humor. The enzyme works by binding to CO2 and facilitating its reaction with H2O, thereby increasing the rate of the reaction.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify an enzyme that is involved in the conversion of CO2 and H2O into carbonic acid.
* **Option B:** This option is incorrect because it refers to an enzyme that is involved in a different biochemical reaction.
* **Option D:** This option is incorrect because it does not specify an enzyme that is involved in the conversion of CO2 and H2O into carbonic acid.
**Clinical Pearl / High-Yield Fact**
Carbonic anhydrase inhibitors are a class of medications that can be used to reduce intraocular pressure by decreasing the production of aqueous humor in the eye. These medications work by inhibiting the activity of carbonic anhydrase, thereby reducing the conversion of CO2 and H2O into carbonic acid.
**Correct Answer: C. Carbonic anhydrase.**