How the Properties of Water are Related to Its Roles in Living Organisms and as a Living Environment for Living Organisms

How the Properties of Water are Related to Its Roles in Living Organisms and as a Living Environment for Living Organisms

Length: 692 words (2 double-spaced pages)

Rating: Better Essays

Open Document

Essay Preview

How the Properties of Water are Related to Its Roles in Living Organisms and as a Living Environment for Living Organisms


Over 70% of the world’s surface is covered by water, 95% of which
consists of salty oceans; water is essential to all life forms. A
molecule of water consists of two hydrogen atoms covalently bound to
one atom of oxygen which gives a formula of H2O. When water molecules
are close together their positive and negative regions are attracted
to the oppositely charged regions of nearby molecules. The force of
attraction, shown in the diagram below as a dotted line, is called a
hydrogen bond. Each water molecule is hydrogen bonded to four others.
It is these hydrogen bonds and the polarity of water molecules which
are responsible for many of the unique characteristics and physical
properties of water. Firstly, the attraction created by hydrogen bonds
keeps water liquid over a wider range of temperature than is found for
any other molecule its size. Secondly, the energy required to break
multiple hydrogen bonds causes water to have a high heat of
vaporization; that is a large amount of energy is needed to convert
liquid water, where the molecules are attracted through their hydrogen
bonds, to water vapour, where they are not.

[IMAGE]


Water bonds itself to other substances very easily which is why some
insects can glide on water. It also has a high surface tension which
means that it is adhesive and elastic. This means that it sticks to
the sides of vertical structures, for example it allows plants to move
water and dissolved nutrients from roots up to the leaves, and allows
the movement of blood through tiny vess...


... middle of paper ...


...nd
a positive end as a result of the polar covalent bonds within the
molecule) water is a solvent and readily interacts with other polar
and charged molecules such as acids, salts, sugars and various regions
of proteins and DNA. The water acts as a solvent for chemical
reactions and helps to transport dissolved compounds into and out of
cells. As a result of these interactions water can dissolve those
substances which are consequently described as hydrophilic (water
loving). In contrast, water does not interact well with non-polar
molecules such as fats, oil and water, and the large polymers (e.g.
polysaccharides and large proteins) do not mix. Non-polar molecules
are hydrophobic (water hating).

Overall, water is necessary for almost all life forms on Earth, and
without it almost nothing would be able to survive.

Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

Check your paper »