water (4)

• why is water biologically important?

  • reactions in living cells take place in cyto, mostly water
  • ideal transport medium- solvent meaning substances dissolve in it
  • plants need it for photosynthesis/support
  • evaporation of water aids cooling
  • water = major habitat
• how is water dipole?

  negatively charged electrons pulled toward oxygen atom, making it slight negative charge. hydrogen atom left with slight positive charge (POLAR MOLECULE)

  • dipole nature= allows hydrogen bonds to form between them (weak but has cumulative effect)
• important properties of water?

  • good solvent
  • high specific heat capacity (energy needed to raise temp of 1 gram of substance by 1 degree)
  • high surface tension (forming hydrogen bonds with other water molecules = cohesion (bond between like molecules, inward force as result which is surface tension)
  • liquid at room temperature