1.7

Question 1

State 4 biologically important properties of water.

Answer 1

-Metabolite / solvent for chemical reactions in the body
-high specific heat capacity
-high latent heat of vaporisation
-cohesion between molecules

Question 2

Explain why water is significant to living organisms

Answer 2

-Solvent for polar molecules during metabolic reactions
-Enables organisms to avoid fluctuations in core temperature
-Cohesion-tension of water molecules in transpiration stream

Question 3

What 5 Properties of water have significant importance in biology. + Explain them.

Answer 3

• is a metabolite in many metabolic reactions, including condensation and hydrolysis reactions
• is an important solvent in which metabolic reactions occur
• has a relatively high heat capacity, buffering changes in temperature
• has a relatively large latent heat of vaporisation, providing a cooling effect with little loss of water through evaporation
• has strong cohesion between water molecules; this supports columns of water in the tube-like transport cells of plants and produces surface tension where water meets air.

Question 4

Why is water a polar molecule?

Answer 4

O is more electronegative than H so attracts the electron density in the covalent bond more strongly
Forms O 𝛿- (slight negative charge) and H 𝛿+ (slight positive charge)