Topic/spec points:
2.1 i) Know the properties of gas exchange surfaces in living organisms (large surface area to volume ratio,
thickness of surface, difference in concentration)
ii) Understand how the rate of diffusion is dependent on these properties and can be calculated using Fick’s
Law of Diffusion.
iii) Understand how the structure of the mammalian lung is adapted for rapid gaseous exchange.
Questions/Keywords/ Notes / diagrams:
definitions:
Draw a simple diagram of
the lungs (to include
trachea, bronchi,
bronchioles, alveoli,
capillaries) and show
where gases are being
exchanged
State Fick’s Law
Apply Fick’s Law to
explain how the lungs are
well adapted for gas
exchange, and explain
why a damaged or
diseased lung would have
reduced gas exchange
Interpret data and explain
in relation to Fick’s law
Use Fick’s Law to explain
why gas exchange in the
lungs may be reduced in
people with certain
conditions
Calculate the surface
area : volume ratio of
different biological
structures
Explain why some
organisms need a
specialised organ for gas
exchange while others
can rely on simple
diffusion
Summary:
,Topic/spec points:
2.2 i) Know the structure and properties of cell membranes.
ii) Understand how models such as the fluid mosaic model of cell membranes are interpretations of data
used to develop scientific explanations of the structure and properties of cell membranes.
Questions/Keywords/ Notes / diagrams:
definitions:
Draw and label a
phospholipid molecule
Explain which part of the
phospholipid is
hydrophilic and which is
hydrophobic
Explain how the
phospholipids are
orientated in the cell
membrane
Draw a labelled diagram
of the molecules found in
a cell membrane (to
include phospholipids,
channel proteins, carrier
proteins, cholesterol,
glycoproteins, glycolipids)
Analyse, describe and
explain data relating (a) to
membrane permeability,
or (b) the uptake of a
substance into a cell.
Explain Singer and
Nicholson’s “fluid mosaic
model” (1972) of the cell
membrane and describe
and explain experiments
which support this model
– to include the fusion of
the human and mouse
membranes by Frye and
Edinin (1970),
freeze-fracture technique
Compare the “fluid
mosaic model” with
previous models of the
cell membrane
Summary:
, Topic/spec points:
2.3 Understand what is meant by osmosis in terms of the movement of free water molecules through a
partially permeable membrane (consideration of water potential is not required)
Questions/Keywords/ Notes / diagrams:
definitions:
Write down the
definition of osmosis
Describe and explain
the mechanism by
which a molecule
crosses the membrane
by osmosis
Describe how to carry
out an experiment
relating to osmosis.
Calculate a percentage
change in mass or
length of plant material
in relation to this. Use
the experiment to
calculate the
concentration of a
solute in a cell.
Summary:
2.1 i) Know the properties of gas exchange surfaces in living organisms (large surface area to volume ratio,
thickness of surface, difference in concentration)
ii) Understand how the rate of diffusion is dependent on these properties and can be calculated using Fick’s
Law of Diffusion.
iii) Understand how the structure of the mammalian lung is adapted for rapid gaseous exchange.
Questions/Keywords/ Notes / diagrams:
definitions:
Draw a simple diagram of
the lungs (to include
trachea, bronchi,
bronchioles, alveoli,
capillaries) and show
where gases are being
exchanged
State Fick’s Law
Apply Fick’s Law to
explain how the lungs are
well adapted for gas
exchange, and explain
why a damaged or
diseased lung would have
reduced gas exchange
Interpret data and explain
in relation to Fick’s law
Use Fick’s Law to explain
why gas exchange in the
lungs may be reduced in
people with certain
conditions
Calculate the surface
area : volume ratio of
different biological
structures
Explain why some
organisms need a
specialised organ for gas
exchange while others
can rely on simple
diffusion
Summary:
,Topic/spec points:
2.2 i) Know the structure and properties of cell membranes.
ii) Understand how models such as the fluid mosaic model of cell membranes are interpretations of data
used to develop scientific explanations of the structure and properties of cell membranes.
Questions/Keywords/ Notes / diagrams:
definitions:
Draw and label a
phospholipid molecule
Explain which part of the
phospholipid is
hydrophilic and which is
hydrophobic
Explain how the
phospholipids are
orientated in the cell
membrane
Draw a labelled diagram
of the molecules found in
a cell membrane (to
include phospholipids,
channel proteins, carrier
proteins, cholesterol,
glycoproteins, glycolipids)
Analyse, describe and
explain data relating (a) to
membrane permeability,
or (b) the uptake of a
substance into a cell.
Explain Singer and
Nicholson’s “fluid mosaic
model” (1972) of the cell
membrane and describe
and explain experiments
which support this model
– to include the fusion of
the human and mouse
membranes by Frye and
Edinin (1970),
freeze-fracture technique
Compare the “fluid
mosaic model” with
previous models of the
cell membrane
Summary:
, Topic/spec points:
2.3 Understand what is meant by osmosis in terms of the movement of free water molecules through a
partially permeable membrane (consideration of water potential is not required)
Questions/Keywords/ Notes / diagrams:
definitions:
Write down the
definition of osmosis
Describe and explain
the mechanism by
which a molecule
crosses the membrane
by osmosis
Describe how to carry
out an experiment
relating to osmosis.
Calculate a percentage
change in mass or
length of plant material
in relation to this. Use
the experiment to
calculate the
concentration of a
solute in a cell.
Summary:
