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

Describe how the properties of water are related to its roles in living organisms and as a living environment for living organisms.

Extracts from this document...

Introduction

Helen Dickens 12SJL Describe 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. ...read more.

Middle

Water vapour is a greenhouse gas, and both the capability to keep heat in and to transfer heat from the tropics serves to buffer temperatures on Earth. For example, as one-half of the Earth rotates away from the sun the fall in temperature is much more gradual than it would have been if there was no water vapour in the atmosphere. As water expands when it freezes it allows ice to float on the surface which creates an insulating layer on lakes and rivers. This prevents the entire body of water and all the organisms living in it from freezing. The weak hydrogen bonding means that ice has a lot of empty space. When ice melts the "frozen" geometry is removed, but not all the hydrogen bonds are broken. The molecules begin to pack more closely together to fill some of the empty space. Thus, liquid water is denser than ice. Water has its greatest density at 4�C and this is why the top of a lake freezes first. ...read more.

Conclusion

This is important for plants because different plants use different parts of the light spectrum for photosynthesis, and the differential absorption can determine the vertical distribution of marine plants. The low viscosity of the water allows organisms to swim and to transport materials through the body. As a result of its polar nature (this means it has a negative end and 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. ?? ?? ?? ?? 1 ...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)

    Cerebro-spinal fluid, amniotic fluid, mucus and pleural fluid (the latter in the lungs). All of these are mainly water, and provide either lubrication or protection and cushion, in different ways. Support The turgidity of plants cells is what keeps them upright, and is down to the fact that the cell

  2. "The Importance of Water and its Properties for Living Organisms"

    Organisms removing waste such as ammonia and urea involves these substances turning into solutions with water. Secreting is another very important function of living organisms. Substances are comprised into aqueous solutions like digestive juices contain salts and enzymes in water.

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

    In plants, mineral salts can only be obtained when in solution, and water makes this possible. Likewise in humans, digestion only occurs when the food is in solution. The reactions of metabolism take place in solution, and also waste products are removed in solution.

  2. The Importance Of Water To Living Organisms

    If it were not for ice floating on water, the oceans would all be frozen solid except for a thin layer of liquid water near the surface. Even the coldest of oceans are liquid except at certain times of year when they may freeze at their surface.

  1. Describe and explain the roles of water in living organisms and as an environment ...

    Water helps to keep the body temperature constant when: the eaten food inside the body is turned into heat energy, this is then turned into action energy for all the daily activities we participate in, but, if the heat builds up, spinal nerves send the signal of "thirstiness" and we naturally consume water to maintain a regular temperature.

  2. Explain How the Properties of Water Make It Suited To Its Functions In the ...

    This allows it to act as a hydrostatic skeleton in organisms such as earthworms and diploblastic organisms like jellyfish. The process of osmosis is only possible because of the size of the water molecule. Because it is so small, water is able to travel through the semi-permiable membrane of cells in living organisms, which larger molecules cannot fit through.

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

    Water can also be used for cooling. This is when evaporation occurs as a lot of heat energy is lost through evaporation. Therefore sweating is an efficient cooling mechanism in humans. The combination of water's thermal stability and solvent properties make it a perfect environment for chemical reactions.

  2. The Role of Water in Living Organisms

    The blood is mostly water, and is used to transport food, hormones, waste products and oxygen. Similarly in plants sap, which contains water, is used to transport food and other substances to the cells. Another use for water is lubrication. The synovial fluid around joints it composed mostly of water.

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