By Dr. Hidemitsu Hayashi, M.D.
Director, Water Institute of Japan
Nisshin Building, 2-5-10 Shinjiku,
Shinjiku-ku, Tokyo, Japan 160
Getting Started: The Basics of
by Dr. Hayashi
Water, The Chemistry Of Life
Whenever we attempt to determine whether there
is life as we know it on Mars or other planets, scientists first
seek to establish whether or not water is present. Why? Because
life on earth totally depends on water.
A High percentage of living things, both plant
and animal are found in water. All life on earth is thought to
have arisen from water. The bodies of all living organisms are
composed largely of water. About 70 to 90 percent of all organic
matter is water.
The chemical reactions in all plants
and animals that support life take place in a water medium. Water not only provides the medium to make these
life sustaining reactions possible, but water itself is often
an important reactant or product of these reactions. In short,
the chemistry of life is water chemistry.
Water, the universal solvent
Standing alone, the hydrogen atom contains one
positive proton at its core with one negative electron revolving
around it in a three-dimensional shell. Oxygen, on the other hand,
contains 8 protons in its nucleus with 8 electrons revolving around
it. This is often shown in chemical notation as the letter O surrounded
by eight dots representing 4 sets of paired electrons.
The single hydrogen electron and the 8
electrons of oxygen are the key to the chemistry of life because
this is where hydrogen and oxygen atoms combine to form a water
molecule, or split to form ions.
Hydrogen tends to ionize by losing its
single electron and form single H+ ions, which are simply isolated
protons since the hydrogen atom contains no neutrons. A hydrogen
bond occurs when the electron of a single hydrogen atom is shared
with another electronegative atom such as oxygen that lacks an
to Alkaline Water Resources