"The Importance of Water to living Organisms"

Authors Avatar

Carl Feldman  

“The Importance of Water to living Organisms”

Water is a unique molecule with certain properties that make it essential to living organisms. Your essay should look at these unique features. You should also explore the many ways in which water is useful to life found on our planet.

        

‘A clear, colourless, tasteless liquid that is essential for plant and animal life’ (1)

Di-Hydrogen Oxide more commonly known as water, the single most important molecule on the planets surface without it life couldn’t exist,   Biologically speaking water is the most abundant compound on this planet. It is the most important component of the human body making up over two thirds of total bodyweight as our cells composition is around 80% water (2), we start life in the womb surrounded by water. Water played a major role in the evolution of biological systems, without it respiration and photosynthesis the very reactions of life couldn’t take place. Water is the medium in which all cell biochemical reactions take place, be it plant or animal. As a result of our understanding of biological systems it is widely accepted that all life originated in water, in an ‘organic soup’ (2). It is also true to say that organisms are so dependant on water that animal migration and behavioural patterns closely follow water availability.

The reason why water is important as a medium for life is mainly attributed to its wealth on the planets surface and from the five properties it exhibits here: Solvent properties, heat capacity, surface tension, freezing properties and transparency (2).

Between 0 and 100°C and at atmospheric pressure water is a liquid. Due to the position of earth in relation to the sun most of the water on the planets surface exists in a liquid state, on other planets such as Venus and Mars water exists as a gas and a solid making it impossible for life to exist. Water readily dissolves a wide range of inorganic and organic molecules, creating what is known as a solution. All chemical reactions within living cells take place in aqueous solution. Water is remarkable its  properties as a solvent are attributed to the fact that it is a polar molecule with positively charged hydrogen atoms and a negatively charged oxygen atom, because of this structure other polar molecules readily dissolve. This is of great importance as most biological molecules are of a polar nature. Another advantage of this polar behaviour is that the individual water molecules are attracted to one another like magnets which means that unlike other small molecules water remains a liquid at room temperature. This attraction is known as ‘hydrogen bonding’ (2).

Join now!

Another interesting property is that it has a very high heat capacity, which means that it takes a lot of energy to make water boil and a large amount of energy must be removed to make water freeze. As a result of this water in our cells and on the planets surface remains at a steady temperature regardless of temperature fluctuations in the environment. This is important as the range of temperatures that biochemical reactions can operate is very small and most organisms cannot survive great variations in temperature.

Surface tension is a very important property of water ...

This is a preview of the whole essay

Here's what a teacher thought of this essay

Avatar

This is an interesting account of the importance of water to living organisms and focuses first on the main properties of water molecules before going on to look at examples of how organisms interact with water in their different habitats. In this respect, the essay takes a different approach to this topic from usual, especially in the second half. Some examination boards might prefer the standard property/biological significance essay but it's good to read a version which tries to steer away from this rather over-used formula. The essay's only major weakness was its lack of appropriate punctuation and capital letters marking the end of one sentence and the start of the next. The scientific content, however, is well researched and fully engages the reader. 4 stars