1.7 Water

Question 1

(Water) Why is water a polar molecule?

Answer 1

Oxygen is more electronegative than H, so attracts the electron density in the covalent bond more strongly.

Form O δ- (slight negative charge) & H δ+ (slight positive charge).

Question 2

(Water) State 4 biologically important properties of water, and what are these due to?

Answer 2

Due to polarirty & intermolecular H-bonds.
- Metabolite/solvent for chemical reactions in the body.
- High specific heat capacity.
- High latent heat of vapourisation.
- Cohesion between molecules.

Question 3

(Water) Explain why water is significant to living organisms. (3)

Answer 3

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