• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Describe the Critical Role That Water Plays In Maintaining Life on Earth, Both as a Constituent of Living Organisms and as an Environment.

Extracts from this document...

Introduction

Describe the Critical Role That Water Plays In Maintaining Life on Earth, Both as a Constituent of Living Organisms and as an Environment One of the most abundant components of all organisms is water. Around 3/4 of the earths surface is covered by water and it makes up 70% of human cells and up to 95% of the mass of a plant. With these kinds of statistics you can see why it is so important. Water is a polar molecule meaning the distribution of electrical charge creates centres of positive and negative charge. These centres are separated by a short distance and the unequal distribution causes the polarity. This polarity makes water a very good solvent. It attracts other charged particles such as ions and other polar molecules. These particles become much more reactive in solutions as they are free to move about and react with other chemicals. ...read more.

Middle

Water also plays a key role in the metabolic breakdown of such essential molecules as proteins and carbohydrates. This process, called hydrolysis, goes on continually in living cells in reactions such as photosynthesis and digestion as its supplies the hydrogen. The high heat capacity of water means that it takes a lot of energy to change the temperature of 1 gram of water by 1�C. As a result of this it means water is very good at maintaining a steady temperature as the hydrogen bonds restrict movement. This is very important for a number of reasons. For example the temperature of oceans and lakes are slow to change, therefore creating a stable habitat for organisms as they do not have to endure rapid and extreme changes. These thermal properties are also important to help mammals whilst maintaining a constant internal body temperature. A great deal of energy is required to change liquids to a vapour so when mammals sweat or pant, the heat used for the vapour to evaporate is lost from the body, therefore cooling it down. ...read more.

Conclusion

At the air/water interface of a pond the cohesion produces surface tensions. This acts almost as a layer of skin over the water. At ordinary temperatures water has the highest surface tension of any known liquid except mercury. Insects, such as pond skaters, exploit this property. The insect's body is supported by the high surface tension allowing them to settle or skate over its surface. Another importance of water is its lubricating properties. Joint are lined with lubricating membranes. These occur in the space between the bones of most joints. The membranes lining the joints are known as synovial membranes. This is because they secrete synovial lubricating fluid. The hollow tracts, such as the respiratory and glandular ducts are also lined with membranes. These membranes are known as mucous membranes because they secrete mucus. It is clear that water plays an important role in many aspects of life. It provides a medium in which all biochemical reactions take place. It is abundant across the surface of the world and has a number of unique properties which promote and sustain life on earth. Katie Finn ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    The roles water in living organisms and water as a habitat for organisms

    5 star(s)

    Sexual reproduction In the process of fertilization, the sperm is transported to the egg in a fluid medium known as semen - this contains mostly water. Density One of the unusual things about water is the fact that the solid form (ice)

  2. Explain how the structure and properties of water relate to the role water plays ...

    remain constantly within limits such that human beings and other living things can survive. If the surface of our world had less water than it does land, the temperature differences between night and day would have been much greater, large regions of land would have been desert, and life might

  1. The roles water in living organisms and water as a habitat for organisms

    Density One of the unusual things about water is the fact that the solid form (ice) is not as dense as the liquid form, and below 4�C the density of water decreases. This property means that ice floats on water and insulates it, reducing the probability of the whole mass of water to freeze.

  2. The Importance Of Water To Living Organisms

    A more obvious property of water is its transparency. This feature of water is very important biologically. Were water opaque very few organisms could live in it, because the absence of light would prevent primary producers from photosynthesising. As light penetrates water, aquatic photosynthetic plants can live at some depth.

  1. Describe how the properties of water are related to its roles in living organisms ...

    Water also absorbs light differentially. The red end of the light spectrum is absorbed in shallow water while the blues and greens penetrate the deepest.

  2. Discuss how the properties of water affect living organisms and why water might be ...

    Examples of reactions which take place in solution are photosynthesis, respiration and excretion. Water is also important for transport. It is used by plants for the uptake of minerals from the soil across the root hairs. All transport fluids in animals are water-based.

  1. Describe the role of Lipids in Living Organisms

    Aquatic mammals such as whales have 'extremely thick subcutaneous fat, called blubber.' (3). The blubber is extremely important in thermoregulation as underwater 'hair is ineffective as an insulation because it cannot trap water in the same way as it can air.'

  2. The Role Of Water In Living Organisms

    Also human digestion will only dissolve soluble foods, meaning large starch molecules must be broken down into soluble sugars.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work