1. Transport of Substances in Blood
Blood transports a variety of substances. The mode of transport of a substance depends on its solubility in water. Research the
following substances and complete the table below.
Substance Mode of transport in blood Explanation
Glucose Dissolved in plasma Because it is polar, glucose is highly soluble
Amino acids Usually dissolved in plasma, but
depends on the amino acid. Not all
amino acids are
Not all amino acids are polar, so all will dissolve. Some require
carrier proteins
Cholesterol Transported in lipoproteins Cholesterol and fats are non-polar which makes them insoluble in
water. Lipoproteins are small molecules made of phospholipids
and proteins that coat the cholesterol/fat molecule, allowing it to
travel in the plasma
Fats Transported in lipoproteins Cholesterol and fats are non-polar which makes them insoluble in
water. Lipoproteins are small molecules made of phospholipids
and proteins that coat the cholesterol/fat molecule, allowing it to
travel in the plasma
Oxygen haemoglobin Oxygen doesn’t dissolve well in plasma (non-polar) so it binds to
haemoglobin
Sodium chloride Dissolved in plasma NaCl is soluble in water. Travels as ions

2. Comparing the Thermal Properties of Methane and Water
Methane and water are both small molecules that have a similar molecular mass. Despite this, they have very different thermal
properties. This is a result of hydrogen bonds forming between water molecules. Because methane is not polar, hydrogen bonds
do not form. As a result, methane has much weaker intermolecular forces (the forces that hold molecules together) than water.
Describe and compare their molecular structures. What is similar, and what is different?
• Both covalent bonds
•
• Both contain hydrogen
•
• Both are small molecules
• Methane is surrounded by hydrogen, meaning it is not polar
• Water has a bent structure, causing it to be polar

3. 1. Complete the table on the next page to compare the thermal properties of methane and water.
Property Definition Methane Water Explanation
Melting Point
The temperature at
which a solid turns
into a liquid
-182 degrees C 0 degrees C Hydrogen bonding means
more energy is required to
separate water molecules and
water is capable of absorbing
more energy before changing
state
Specific heat capacity
Water is able to
absorb or give off a
great deal of heat
without changing
temperature greatly.
2.2 J per g per
degree C
4.2 per g per degree
C
Latent heat of
vaporisation
Water absorbs a
great deal of heat
when it evaporates, it
is used as a cooling
mechanisms in many
organisms including
ourselves in the form
of sweat.
760 J/g 2257 J/g
Boiling point
The temperature at
which a liquid turns
into a gas
-160 degrees C 100 degrees C