water Flashcards
1
Q
What type of molecule is Water?
A
Polar
oxygen = negative
hydrogen = positive
2
Q
What type of bonding occurs between water molecules?
A
hydrogen bonding
3
Q
Give 5 important properties of water
A
- High specific heat capacity
- High latent heat of evaporation
- Cohesive
- Metabolite
- Solvent
4
Q
Explain high specific heat capacity [2]
A
- Polar so many H bonds form between water molecules
- These allow water to absorb a relatively large amount of heat energy before its temperature changes
5
Q
Why is high specific heat capacity an important property? [2]
A
- Makes a stable habitat
- Organisms mostly made of water so helps maintain a constant internal body temperature
- important as temperature affects enzyme activity
6
Q
Explain high latent heat of evaporation [2]
A
- Polar so many H bonds form between water molecules
- These can absorb a lot of energy before breaking, when water evaporates
7
Q
Why is high latent heat of evaporation an important property? [1]
A
- Evaporation of small amount of water (e.g. sweat)
is an efficient cooling mechanism - helping organisms maintain a constant body temperature
8
Q
Explain cohesion [2]
A
- Polar so many H bonds form between water molecules
- So water molecules tend to stick together
9
Q
Why is cohesion an important property? [2]
A
- Column of water doesn’t break when pulled up a narrow tube
e.g. xylem during transpiration - Produces surface tension at an air-water surface so invertebrates can walk on water
e.g. pond skaters
10
Q
Explain water as a solvent [2]
A
- Polar (has a slightly positive and negative ends)
- Can dissolve ionic compounds
11
Q
Why is water being a solvent an important quality? [2]
A
- Acts as a medium for metabolic reactions
- Acts as a transport medium
e.g. in xylem to transport nitrates which are needed to make amino acids
12
Q
Explain water as a metabolite [1]
A
- Water is reactive
13
Q
Why is water being a metabolite an important quality? [2]
A
- Condensation releases H2O and forms a chemical bond
- Hydrolysis requires H2O to break a bond
