Water Flashcards
What is water?
A polar molecule with an uneven distributions of charge with delta+ hydrogen and delta- oxygen allowing hydrogen bonds to form
What properties make water essential for life?
- Water as a solvent
- Water is a metabolite
- High specific heat capacity
- High latent heat of vaporisation
- Cohesion
- High surface tension
- High density
- Transparency
Why is water being a solvent essential for life?
Called the universal solvent. Because it is polar, it attracts charged ions and other polar molecules that dissolve in water, to be transported and used in biochemical reactions e.g. glucose
Why does water being a metabolite make it essential for life?
It is used in many biochemical reactions as a reactant e.g. photosynthesis
Also used in many hydrolysis reactions or condensation reactions
Why does a high specific heat capacity make water essential for life?
Large amount of energy is needed to raise the temperature as hydrogen bonds restrict movement, so increases in KE are resisted.
This keeps aquatic habitats stable and allows enzymes in cells to work efficiently
Why does water having a high latent heat of vaporisation make it essential for life?
Lots of energy is required to change it from liquid to vapour,
Can be used for temperature control e.g. heat used to vaporiser water from sweat on skin, or from leafs surface, as it evaporates, body cools
Why does cohesion make water essential for life?
Cohesions is the attraction of water molecules to each other due to the hydrogen bonds formed due to the dipole structure
Although weak, because there are so many hydrogen bonds, the molecules stick in a lattice,
This allows columns of water to be drawn up the xylem in plants
Why does high surface tension make water essential for life?
Cohesion between water molecules at surface produces surface tension, so body of insects like pond skater is supported.
Water has highest surface tension of any liquid beside mercury
Why does waters high density make it essential for life?
Water is more dense than ice, so the ice floats, creating an insulating layer, prevent water from losing heat and completely freezing, so aquatic organisms can survive
Why does water being transparent make it essential for life?
Allows ligh to pass through so aquatic plants can photosynthesise
What is a hydrolysis reaction?
Breaking down of large molecules into smaller molecules by addition of a molecule of water
What is a condensation reaction?
Chemical process in which two molecules combine to form a more complex molecule, with the elimination of a molecule of water
