Water

Question 1

Importance of water

Answer 1

• vital for living organisms its 80% of cells contents
• metabolite in loads of important metabolic reactions
• solvent
• helps with temp control (high latent heat of vaporization and high specific heat capacity)
• cohesive - helps water transport

Question 2

Polarity of water

Answer 2

• shared negative hydrogen electrons are pulled towards oxygen atom
• other side of hydrogen left with slight positive charge
• unshared negative electrons on oxygen give it a slight negative charge
• polar molecule = slight negative charge on 1 side and slight positive charge on another side

Question 3

hydrogen bonding

Answer 3

• weak bonds between a slightly positively charged hydrogen atom in one molecule and a slightly negative charged atom in another molecule
• hydrogen bonds form between water molecules because slightly negatively charged oxygen atoms of water attract slightly positively charged hydrogen atoms of other water molecules

Question 4

Good Solvent

Answer 4

• ionic which means its made from 1 positively charged atom or molecule and one negatively charged atom or molecule
• water is polar so ions will get totally surrounded by water molecules which means its able to dissolve
• water polarity makes it useful as a solvent
• living organisms can take up useful substances dissolved in water and these dissolved substances can be transported around the organisms body.

Question 5

high latent heat of vaporisation

Answer 5

• water evaporates when hydrogen bonds are broken which allows water molecules on the surface to escape into air as a gas
• takes a lot of energy to break the hydrogen bonds so a lot of energy is used up when water evaporates
• water = high latent heat of vaporization
• useful because use water loss through evaporation to cool down without losing too much water
• when water evaporates it carries away heat energy from a surface, which cools surface and helps to lower temperature

Question 6

Can Buffer (Resist) Changes In Temperaturw

Answer 6

• hydrogen bonds give water a high specific heat capacity
• water heated a lot energy needed to break hydrogen bonds
• less heat energy available to actually increase the temperature of the water = high specific heat capacity
• useful because water doesn’t experience rapid temperature changes
• water a good habitat as underwater more stable then on land
• water inside organisms also remains at a stable tempo maintaining constant internal body temp

Question 7

Very Cohesive

Answer 7

• cohesion = attraction between molecules of the same type
• water very cohesive because their polar
• strong cohesion helps water flow making it great for transporting substances which also means water has a high surface tension when it comes to contact with air