The roles of water in living organisms,and as an environment for organisms.

Water is vital to life, with out water life on earth would cease to exist as every living organism must have water in order to survive. The total amount of water on Earth is fixed, (75% of the earth is covered in water) and most is recycled and re-used. The largest reservoirs are oceans and open seas. Very little is actually contained within living organisms, although water is a major constitute of most life forms. Water is a major component of cells, typically forming between 70 and 95% of the mass of the cell. Therefore humans are made from approximately 80% water by mass as opposed to some soft bodied, aquatic creatures such as jellyfish are made of up to 96% water. Water also provides an environment for organisms to live in. this is why when space probes are dispatched to other planets in search of life they look for the presence of water to determine if life is possible there.
Water itself is a simple chemical compound, each molecule composed of 2 hydrogen atoms and one oxygen a...