Topic 2.2: Water Flashcards
Water composition
H2O
Water polarity
a) Oxygen has a higher electronegativity and attracts shared electrons more strongly.
b) Polar (S- / S+ / S+)
Hydrogen bonds
Dipolarity of H2O enables it to form polar associations with other charged molecules.
Cohesion
Like molecules stick together (Hydrogen bonds).
Adhesion
Unlike molecules stick together (Hydrogen bonds)
Consequences of the cohesive properties of H2O
High surface tension.
Supporting animals
Consequences of adhesive properties of H2O
Capillary action
Movement of water up
Biological important elements
a) Ca
b) Fe
c) Mg
d) P
e) S
f) Na
g) K
Solvent properties of H2O
a) Universal solvent (Polar / Ionic)
b) Formation of hydration shells.
Hydrophilic
Substances that can dissolve in H2O
Hydrophobic
Substances that cannot dissolve in H2O.
Solvency in H2O of:
a) Glucose
b) Amino acids
c) NaCl
d) Oxygen (low)
Hydrophilic
Solvency in H2O of:
a) fats
b) cholesterol
Hydrophobic
Lipoproteins
Importance of solvent properties of H2O
Medium for metabolic reactions
Transport medium
Thermal properties of H2O
a) Absorb large amounts of heat energy before undergoing a change of state.
b) Very high specific heat capacity.
