Water

• Water is a polar solvent and can transport many biological molecules as they are also polar and can be dissolved in water.
• Water has a high heat specific capacity, requiring a lot of energy to change its temperature, which helps minimize temperature fluctuations in living things, an important part of homeostasis.
• Features of a mass transport system

  • A network to move through (e.g., vessels)
  • A medium for movement (a fluid e.g., blood)
  • Controlled direction - to move substances to/from where they are needed
  • Maintenance of speed
• Hydrogen bonding between water molecules creates cohesion and adhesion, facilitating the transport of water and dissolved substances.
• Transport of Substances

  Animals require essential substances to enter and leave the body in sufficient quantities and be transported around the body. Small organisms can rely on diffusion due to their large surface area to volume ratio. As organisms increase in size, diffusion becomes insufficient, leading to the need for a mass transport system consisting of the heart and circulation to move substances and allow exchange.
• Water is a polar molecule, with hydrogen atoms having a partial positive charge and the oxygen atom having a partial negative charge, enabling effective transport of water and dissolved substances through xylem vessels.
• A certain amount of energy is required to change the temperature of water, minimizing temperature fluctuations in living things (an important part of homeostasis)
• Mass transport


  The bulk transport of substances to all parts of an organism using mass flow
• Dipole

  A molecule with an unequal distribution of electrons causing atoms in the molecule to have partial charges
• Solvent


  A substance in which solutes can dissolve to form a solution