2.4) Water and its functions Flashcards
What is a dipolar water molecule?
A water molecule that contains 2 hydrogen atoms and 1 oxgen atom
Why is a a water molecule dipolar?
Beacuse Oxygen has a slight negative charge and Hydrogen has a slight positive charge
Water and Hydrogen Bonding:
- The opposite charges on water molecules attract forming hydrogen bonds
- H bonds are weaker than covaelnt bonds but gives water its unique properties
What are the 3 main properties of Water?
1) Specific Heat Capacity
2) Latent Heat of Vaporisation
3) Cohesion and Surface Tension
Why is Specific Heat Capacity relevant to Water?
- Water has a high specific heat capacity because of hydrogen bonding
- Absorbs lots of heat without a large temprature rise ( helps organisims regulate their temprature)
Why is Latent Heat of Vaporisation relevant to Water?
- Water requires a lot of energy to evaporate
- Makes sweating an efficent way to cool down
Why is Cohesion and Surface Tension relevant to Water?
- Water molecules stick toegther (Cohesion) due to H bonds
- Allows water to be pulled through xylem vessels in plants
-Surface Tension supports small organisims like pond skaters
Why is Water important to living organisims?
- Metabolisim
- Solvent
- Other features ( Body Temp, Transparency)
Why is Water important in Metabolisim?
- Water is involved in Hydrolysis
- Used in photosynthesis
Why is Water important in Solvents?
- Water dissolves many substances
- Waste: Ammonia, Urea
- Hydrophillic Molecules: Amino Acids, ATP
Where are Inorganic Ions found?
- Inorganic Ions are found in cells and fluids
E.g. Iron in haemoglobin for oxygen transport
Phosphate Ions in DNA + ATP for energy storage
State and explain the property of water that can help to buffer changed in temperature
Water has a high specific heat capacity which means it requires a lot of heat to change temperature
