ABSTRACT
In living cells, there are many circumstances when catalysis of hydration/dehydration is needed. The enzymes that perform this catalysis are carbonic anhydrases. There are significant amounts of carbon dioxide in the atmosphere, and also in most natural water systems near the surface of the Earth. The prevalence of dissolved carbon dioxide (CO2) means that CO2 plays some role in determining the pH of virtually all natural waters. Dissolved CO2 is added to water by organisms carrying out respiration. Dissolved CO2 is removed from lakewater by algae carrying out photosynthesis. This can occur over large portions of lakes and sections of the oceans during algae blooms. The in-situ pCO2 measures the contribution that the dissolved CO2 could make (along with all other dissolved gases plus water itself) to form a bubble against the ambient pressure. If the sum of the contributions becomes larger than the system, a bubble can form.
