properties of water

• because water is liquid at room temp it can:

  • provide habitats for living things in rivers, lakes and sea
  • major component of the tissues in living organisms
  • provide a reaction medium for chemical reaction
  • effective transport medium eg blood
• because ice is less dense than water

  • aquatic organisms have a stable environment in which they live through winter
  • ponds and other bodies of water are insulated against extreme cold, the layer of ice reduces the rate of heat loss from the heat of the pond
• because water is a good solvent:

  • molecules and ions can move around and react together in water, reactions in the cytoplasm of cells which is over 70 % water
  • molecules and ions can be transported around living things whilst dissolved in water
• cohesion and surface tension

  • H bonding between the molecules pulls them together = cohesion
  • water contacts = surface tension
  • columns of water in plants vascular tissues are pulled up the xylem tissue together from the roots
  • insects like pond skater can walk on water
• high specific heat capacity

  • living things and including prokaryotes and eukaryotes need a stable temp for enzyme controlled reactions to happen properly
  • aquatic organisms need a stable environment in which to live in
• high latent heat of vaporisation

  • help molecules break away from each other to become gas molecules
  • large amount of energy needed for water molecules to evaporate
• reactant

  • water is a reactant in reactions like photosynthesis and hydrolysis reaction such as digestion of starch, proteins and lipids