1.7 Water

• Explain how hydrogen bonds occur between water molecules

  ● Water is polar molecule and a major component on cells ● Slightly negatively charged oxygen atoms attract slightly positively charged hydrogen atoms of other water molecules

  
• Explain properties of water that are important in biology - Metabolite


  Metabolite

  Used in condensation / hydrolysis / photosynthesis / respiration
• Explain 5 properties of water that are important in biology - Solvent


  Solvent (can dissolve solutes)

  1. Allows metabolic reactions to occur (faster in solution)

  Allows transport of substances eg. nitrates in xylem, urea in blood
• Explain 5 properties of water that are important in biology - High specific heat capacity


  High specific heat capacity

  ● Buffers changes in temperature

  ● As can gain / lose a lot of heat / energy without changing temperature

  1. Good habitat for aquatic organisms as temperature more stable than land

  Helps organisms maintain a constant internal body temperature
• Explain 5 properties of water that are important in biology - High latent heat of vaporisation

  High latent heat of vaporisation

  ● Allows effective cooling via evaporation of a small volume (eg. sweat)

  ● So helps organisms maintain a constant internal body temperature
• Explain 5 properties of water that are important in biology - Strong cohesion between water molecules

  Strong cohesion between water molecules

  1. Supports columns of water eg. transpiration stream through xylem in plants

  Produces surface tension, supporting small organisms (to walk on water)