water

Question 1

Explain how hydrogen bonds occur between water molecules

Answer 1

● Water is polar molecule
● Slightly negatively charged oxygen atoms attract slightly positively
charged hydrogen atoms of other water molecules

Question 2

what are 5 properties of water that are important in biology

Answer 2

metabolite
solvent
high specific heat capacity
high latent heat of vapourisation
strong cohesion between water molecules

Question 3

Explain the property metabolite of water that is important in biology

Answer 3

Used in condensation / hydrolysis / photosynthesis / respiration

Question 4

Explain the property solvent of water that is important in biology

Answer 4

1. Allows metabolic reactions to occur (faster in solution)
2. Allows transport of substances eg. nitrates in xylem, urea in blood

Question 5

Explain the property high specific heat capacity of water that is important in biology

Answer 5

● Buffers changes in temperature
● As can gain / lose a lot of heat / energy without changing temperature
1. Good habitat for aquatic organisms as temperature more stable than land
2. Helps organisms maintain a constant internal body temperature

Question 6

Explain the property high latent heat of vaporisation of water that is important in biology

Answer 6

● Allows effective cooling via evaporation of a small volume (eg. sweat)
● So helps organisms maintain a constant internal body temperature

Question 7

Explain the property strong cohesion of water molecules that is important in biology

Answer 7

1. Supports columns of water eg. transpiration stream through xylem in plants
2. Produces surface tension, supporting small organisms (to walk on water)