The Biological Significance Of The Properties Of Water

The Biological Significance Of The Properties Of Water

The human body 15% lipids, 12% proteins but by far the biggest % is

water which makes up a massive 70% of the human body. This is the

equivalent of 49kg in an average male adult human of mass 70kg. This

is a good indication of just how important water is in the human life.

Without water we would not be able to life and Earth is therefore the

only planet in this galaxy with life as we know it except for Mars

where ice has been discovered so water may have been present once.

Water is a polar molecule, meaning that it has a positive and a

negative pole. This is due to the fact that the water is an oxygen

atom covalently bonded to 2 separate hydrogen ions to fill its outer

shell by sharing electrons. However in the oxygen nucleus there are 8

protons but there is only 1 in each hydrogen nucleus. This results in

the 2 shared electrons being slightly more attracted to the oxygen

nucleus than the hydrogen nuclei. This means that the oxygen end of

the molecule has a slightly negative charge (S-) and the 2 hydrogen

ends have a slightly positive charge (S+). These molecules now join

together because each positive end is attracted to a negative end of

another molecule and vice-versa. These bonds between the charged poles

are called hydrogen bonds.

All this means that water has several very useful properties which

help living organisms to survive.

The polarity allows the molecules attract to each other and although

these hydrogen bonds are only 1/20th of the strength of a covalent

bond, collectively they still make the water molecules 'stick

together' strongly and give them a high su...

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...with a safe habitat under the ice which floats on

the surface of the water because it is less dense. Under the ice the

animals are protected from some predators and the environment is kept

constant and insulated which helps them maintain a constant body

temperature. The ice floats on the surface tension of the water and

provides other animals with a place to live. If the ice sank to the

bottom then the water would freeze from the bottom and eventually

there would be no water left and many animals would die.

In conclusion, water is very important to human life and all other

organisms as it is evident that without it many would become extinct.

It is the fact that water is polar and has hydrogen bonds that give it

the properties described and it is these properties that make water so

indispensable to life as we know it.