Water

• What are the 5 core properties of water?

  1. Cohesion
  2. High latent heat of vaporisation
  3. High specific heat
  4. Important solvent
  5. Is a metabolite
• Metabolite

  Water is involved in many metabolic reactions, such as photosynthesis and hydrolysis.
• Important solvent

  Water is dipolar so can dissolve other charged molecules.

  This is useful in the body as drugs, salts, urea and hormones can be dissolved to reduce their toxicity.

  It also aids transportation of substances within blood plasma.
• High heat capacity.

  Large amount of energy is needed to heat water. This allows for thermostable aquatic environments.
• Large latent heat of vaporisation.

  Large amount of energy needed to vaporise water. This means that a cooling effect can be provided to the body with little loss of water through evaporation (sweat).
• Cohesion

  Water molecules stick together due to polarity.

  This supports columns of water in the tube-like transport cells of plants and provides surface tension where water meets air.
• Additional properties of water

  Transparent (photosynthesis)

  Ice is less dense than water (insulation)

  High surface tension (useful to small insects)

  Needs to lose lots of heat energy before freezing (prevents excessive damage to organisms as slow freezing of cells)
• Bonding

  Strong intramolecular forces (covalent bonds), weak intermolecular forces (hydrogen bonds).