The Biological Importance of Water

Waters viscosity is another important aspect to the organisms relying upon it; this is because it easily flows and so can move easily through blood vessels and plants xylem and phloem vessels. The lower the viscosity the less energy required to transport the solution. So water is quite good for the transport of biological fluids.

Water is a liquid at room temperature, this in itself is quite surprising considering the other substances that are in its group are all gases at room temperature and have very low boiling points from -5°C onwards. However, water has a boiling point of 100°C, which is useful because it won’t boil until it reaches very high temperatures.

Another one of the wonders that water has is its high latent heat of vaporisation. This is shown when water is heated to boiling point 100°C the waters temperature does not increase even if more heat is added. The excess energy is used by the liquid turning into the gas water vapour. Many biological mechanisms rely on waters ability to do this; one of these is the human’s main method of thermo regulation. Sweating is when the water is evaporated off the body taking the excess heat with it and thus cooling the organism down.

The main reason that water has these unusual properties is the way it is chemically. Each water molecule has the two hydrogen particles and one oxygen particle. This is where the abnormality is shown the oxygen having a higher number of protons in the centre attracts the two shared electrons given from the covalent bond more frequently giving the oxygen side a more negative charge to where the hydrogen side is. This means that the water molecule arranges its self with other water molecules so that the oxygen is touching the hydrogen atoms. This is called a dipole. The slight charges are represented by a δ+ or δ- depending on the charge.

As well as making a suitable environment where metabolic reactions can take place, water in its self takes part as a reactant in some reactions. Two of the main ones are photosynthesis and of course digestion.