Why is water necessary for life? ?

Question

Why is water necessary for life? ?

Answer 1

This is not a dumb question. Not long ago is was considered a fact that carbon and sunlight were critical for life to exist. The history of science is littered with examples of facts that turned out to not be facts after all. Turns out carbon and sunlight are in 'fact' not prerequisites for life.

What about water? I will stick my neck out and bet that water is necessary for life. It is commonly considered so for the following reasons.

It is a the universal solvent. Molecules and compounds can be dissolved in it and removed from it easy. This is because it is the only molecule that can simultaneously be an acid and a base as follows.

H20 <---> H+ + OH-

            (acid) + (base/alkali)

Therefore the transport of every element/nutrient required for building a life form is facilitated exceedingly effectively by water. Because ions freely exist in water it is also a great electrolyte allowing electrical charges to be formed, which power nerves, muscles and basic cellular processes.

Transposing this to the real world. We have yet to find an organism that doesn't need water to live. Bacteria has been found living kilometers into the Earth's mantle rock living off minerals found in the rocks and pore-water inclusions. This isn't proof that water is essential and it is likely that is it impossible to get absolute proof of this.

What about elsewhere in the universe. Again, it is unlikely that life has developed without water. Hydrogen is the most abundant element in the universe and oxygen is a massive component of supernovae. Therefore it is probable that water is reasonably abundant in the universe. Given what we know about this amazing molecule on a chemical level and what we know about life, it is likely that all life arose only where you have the basic and unique atomic characteristics of water.

Answer 2

because without it you body would dry up and shrivel up.....which would kill you.  

Answer 3

cause dense air can turn into water.

Answer 4

you're 2/3 water, smart one.