Water and the Fitness of the Environment

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amount of something.

Acidic and Basic Conditions affect Living Organisms

Effects of change in pH

A water molecule can transfer H+ to another water molecule to form H3O+ and OH-. Acids are substances that produce hydrogen ions in aqueous solution. Bases are substance that produce hydroxide ions in aqueous solution. Acids and bases affect the pH level. In any aqueous solution at 25°C, the product of the H+ and OH- concentrations is constant at 10^-14. The pH of a solution is defined as the [- log 10] of the hydrogen ion concentration. In a neutral solution, [H+] is equal to 10−7 M. Each pH unit represents a tenfold difference in H+ and OH− concentrations. The internal pH level in most organism is 7. Cells are sensitive to ph change, as a result, biological fluids have buffers, which resist changes in the pH. Buffers accept hydrogen ions from the solution when they are in excess and donate hydrogen ions when they have been depleted.

Buffers consist of a weak acid and its corresponding base. Ex: carbonic acid (H2CO3).

Buffers are like cops. Buffers regulate pH level, while cops regulate criminal activity.

Threats to water quality on earth

Human activities release of large amounts of CO2 that increases pH level and temperature of the atmosphere. The burning of fossil fuels and electric power plants produce oxides which react with water and results in acid precipitation. About half of the CO2 produced stays in the atmosphere and prevents heat from radiating into outer space and 30% of CO2 is absorbed by water bodies. When CO2 dissolves in seawater, it can react with water to form carbonic acid which lowers the pH level and causes reduction in carbonate ion in water. Studies have shown that the production of calcium carbonate by corals and other organisms, is directly affected by the concentration of carbonate. In the study, Biosphere-2, Chris Langdon and his colleague used artificial coral reef system in which the temperature and chemistry of the seawater can be controlled and manipulated to test the effects of varying the concentration of carbonate on the rate of calcification in the coral reef. It was concluded, that the doubling of CO2 emissions by 2065 could lead to a 40% decrease in coral reef calcification.

Example of CO2 effect is global warming.

Water is like a tree whose importance is immense, but no one gives it any value.