IB Biology HL D2.3.1 Solvation with Water Questions
Analyse how polar water molecules hydrate ions and polar solutes and support aqueous dissolution in IB Biology HL D2.3.1.
- Syllabus
- First assessment 2025
- Course
- Biology HL
- Level
- HL
Analyse how polar water molecules hydrate ions and polar solutes and support aqueous dissolution in IB Biology HL D2.3.1.
Hydrogen bonds can exist both within and between molecules in living organisms and have an impact on their structure and function. Explain the importance of hydrogen bonding for living organisms.
a. cohesion in water/water molecules stick together (due to hydrogen bonds)
b. cohesion helps transport under tension of water/sap in xylem / transpiration stream
c. adhesion between water and cell walls/cellulose/polar molecules
d. adhesion/capillary action helps water to rise in plants/stems/xylem / helps keep leaf walls moist
e. solvent properties (due to hydrogen bonds) with polar/hydrophilic molecules
f. solvent properties exemplified by glucose/other example of a polar solute
g. high latent heat of evaporation / (much) energy required for evaporation so water useful as coolant/for sweating
h. high (specific) heat capacity so water temperature changes less
i. base pairing between bases/nucleotides/strands in DNA by hydrogen bonding
j. base pairing between bases in RNA and DNA for transcription/between codon and anticodon for translation
k. proteins have hydrogen bonding in secondary structure/α helix/β pleated sheet
I. proteins have hydrogen bonding between R groups/in tertiary structure/to maintain conformation
m.habitats because water is liquid due to high boiling point/due to water freezing on the surface
n. habitats on water surface due to surface tension