Water and its importance to living things

Think of what it is you need to survive...Water. Water is essnetial to life itself. Without water life on earth would not exist. It is a major importance to living things, in some organisms up to 90% of their body weight derives from water, the brain is composed of 70% water, and 60% of the human body is water and up to 70-95% of the mass of cells is water.

It also provides an enviroment for organisms to live in, 75% of the earth is covered in water.

Water is a simple molecule made up of an oxygen atom and two hydrogen atoms, H2O.

A pair of electron is shared between an oxygen atom and a hydrogen atom,

These electrons are not shared equally, the oxygen has a slight negative charge and the hyrdogens have a slight positive charge. This leaves an unequal charge of distribution, known as a dipole. When water molecules are close together the positively charged hydrogen atoms are attracted to the negatively chraged oxygen atoms, to form a weak hydrogen bond. The bonds are weak but a large number of the molecules put together provides a large enough force to keep keep the molecules together. Because water is a polar molecule, it can dissolve other polar or ionic substances.

Molecules that are attracted to water or dissolve in it are known as hydrophillic substances.

Water can seperate covalantely bonded molecules such as glucose, this is because the hydroxyl groups (-OH) in its structure forms hydrogen bonds with the water, this seperates the molecules from one another. Most biochemical reactions such as respiration occur in solutions, so it is vital that water is a solvent. Water has a high specific heat capacity, this means that to raise a 1g of water to 1°C you need 4.2J of energy, this therefore means that alot of enrgey is required to raise ...

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Molecules that are attracted to water or dissolve in it are known as hydrophillic substances.

The density of water increases as it cools. The hydrogen bonds between the water molecules develop a lattice structure. The denisty of ice is lower than water, we knows this because ice floats on water. The thin layer of ice insulates the water below, making it possible for aquatic life to continue. Wahta are the phydicsl sides of the new bargain elements are beingf sided along

Water is the main enviroment/ medium for many reactions, especially those occuring in cells. In condensation reactions water is the main ingredient, where water is removed from molecules to bond them together. This occurs with many sugars and carbohydrates.

Hydrolysis is used as mean of splitting up moilecules. It is essential to animals and plants, this is because it allows them to make use of stored food, which are in long chains. Water molecules are highly cohesive because of the hyrdrogn bonds between the molecules. This property of water allows plants to pull up water through xylem vessels from the roots to the leaves. The water molecules that meet the air will be tightly held together and the water molecules below them form an elastic film known as the surface tension. Water has strong hydrostatic forces, because of this water is incompressible. This is supportive for soft bodied creatures such as worms and slugs, both of which do not have a skeleton. Cells that are filled with water become turgid and because of water being incompressible plants can support themselves.

It also readily dissolves most salts, however it is a poor solvent for proteins and other large organic molecules in living cells. This means that water can transports many nutrients to the cells without dissolving or destroying the contents of the cell. Water can also transport waste products from the cells. Water enters the cells protoplasm but does not dissolve in it, an increase in water leads to an increase in chemical activity within the cell. This means that majority of the distribution on earth is highly dependant on water. Our needs will be affected by the distribution and the availability of water.

Water has unique qualities and properties that make it so important to life. Water has an excellent ability to dissolve in many substances.

What are the physical and chemical properties of water that make it so unique and necessary for living things? Looking at water, it has no taste or smell, and is virtually colourless, what could be more boring, but its the hidden qualities of water that make it so intresting.

Waters chemical properties

As we already know that waters chemical discription is H2O. The opposite electrical charges tend to attract the water molecules to one another, making water almost sticky. These water molecules clump together this is why water drops are drops. Water is known as a universal solvent, because it dissolves more substances more than any other liquid, becuase water molecukes are attracted to them. This means that where ever water goes either through the ground or body it takes valuable chemicals, minerals or nutrients along with it.

Waters Physical Properties

It is unique because it is the only natural substance that is found in three states, liquid, slid and gas.
Unusual because its solid form is lkess dense then the lquid form, which is why ice floats.
Can absorb alot of heat energy before it gets hot. This is why it is valuable in industries and in car radiators as a coolant. But u r now i cant be myslefwitr
Has a very high surface tension, in other words it is sticky and elastic and tends to clump togetherin drops rather than out in a thin film. Surface tension is good for capillary action. This allows water to move though roots of plants and thorugh the tiny blood vessels in our bodies.

After doing this i have found out that, even though a weater molecule seems to be very simple and has a structure not so complex as others, it has many specila properties and without these special properties and funcxtions we would not be able to live on this planet.

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