2.2 Bio Molecules

Question 1

How does water work as a solvent?

Answer 1

• Polar
• So ions and covalently bonded polar substances (glucose) can dissolve in it
• Chemical reactions can therefore occur easier (dissolved solutes more free to move around so are more chemically reactive)
• Metabolites can be transported efficiently (except for non polar ones because they are hydrophobic)

Question 2

Advantages of Water having a high Specific Heat Capacity

Answer 2

• Temp of water doesn’t fluctuate much
• Can provide a suitable habitat

OPTIMAL TEMPERATURE MAINTAINED WITHIN CELLS AND THE BODY

• Temperatures remain fairly constant which is important for optimal enzyme activity
• Water in blood plasma transfers heat around body
• In warmer regions, more blood passes through, and heat energy is absorbed by water to cool these areas of the body, while the temp of the water doesn’t fluctuate much

Question 3

How is a high latent heat in water useful?

Answer 3

• Lots of energy required to evaporate water to water vapour
• So little water is required to evaporate for organism to lose a great amount of heat energy
• So sweating in skin or transpiration in leaves gives a COOLING EFFECT