Properties of Water

Solvent
1. Metabolic processes in all organisms rely on chemicals being able to react together in solution
2. 70-95% of cytoplasm is water. Dissolved chemicals take part in processes such as repiration and photosynthesis in living organisms
Liquid
1. The movement of materials around organisms, both in cells and on a large scale in multicellular organisms, requires a liquid transport medium
2. Blood in animals and teh vascular tissues in plants use water as a liquid transport medium
Cohesion
1. Water molecules stick together creating surface tension at the water surface. Cohesion also makes long, thin water columns very strong and difficult to break
2. Transport of water in teh xylem relies on water molecules sticking together as they are pulled up the xylem in the transpiration stream
3. Some small organisms make use of surface tension and have the ability to 'walk on water'
Freezing
1. Lakes tend not to freeze completely so aquatic animals are not killed as temperatures fall
2. Water freezes, forming ice on the surface. Water beneath the surface becomes insulated and less likely to freeze
Thermal Stability
1. Large bodies of water have fairly constant temperatures
2. Evaporation of water can cool surfaces by removing heat
3. Oceans provide a relatively stable environment in terms of temperature
4. Many land-based organisms use evaporation as a cooling mechanism, for example in panting or sweating
Metabolic
1. Water takes part as a reactant in some chemical processes
2. Water molecules are used in hydrolysis reastions and in the process of photosynthesis

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Properties of Water

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	Erstellt von Katie Kenney vor fast 10 Jahre