1.7 Water Flashcards
1
Q
Water is a … molecule.
A
dipolar
2
Q
Name 6 properties of water.
A
- a solvent
- high specific heat capacity
- high latent heat of vaporisation
- a metabolite
- cohesion
- adhesion
3
Q
What is the role of water being a solvent for living organisms?
A
- many molecules can dissolve in water allowing chemical reactions to occur within cells
- metabolites can be transported efficiently
4
Q
Why is water a solvent?
A
Water is a polar molecule.
5
Q
What is the role of water having a high specific heat capacity for living organisms?
A
- allows water to be a suitable habitat
- buffers temperature changes so optimal temperature is maintained → vital in maintaining temperatures that are optimal for enzyme activity
6
Q
What is the role of water having a high specific latent heat of vaporisation for living organisms?
A
- provides a cooling effect for living organisms
- (e.g. evaporation of water in sweat, transpiration)
7
Q
What feature of water allows it to have a high shc and slh of vaporisation?
A
Many hydrogen-bonds.
8
Q
In which processes is water a metabolite?
A
- condensation
- hydrolysis
- photosynthesis
- respiration
9
Q
What does cohesion between water molecules allow?
A
- supports transpiration stream in plants
- produces surface tension to support small organisms
10
Q
What does adhesion between water molecules and other molecules allow?
A
- enables water to move up the xylem as water forms hydrogen bonds with cellulose.
11
Q
Exam Q: Explain 5 properties that make water important for organisms
A
- A metabolite in condensation/hydrolysis/ photosynthesis/respiration;
- A solvent so (metabolic) reactions can occur
OR
A solvent so allowing transport of substances; - High (specific) heat capacity so buffers changes in temperature;
For ‘buffer’ accept ‘resist’. - Large latent heat of vaporisation so provides a cooling effect (through
evaporation); - Cohesion (between water molecules) so supports columns of water
(in plants)/ transpiration stream - Cohesion (between water molecules) so produces surface tension
supporting (small) organisms;
For cohesion accept hydrogen bonding