MEDIUM
AS and A Level
IMPORTANT
Earn 100
Why does the cell surface membrane not provide a barrier to the entry of hydrophobic molecules into the cell?
Important Questions on Cell Membranes and Transport
MEDIUM
AS and A Level
IMPORTANT
Suggest three reasons why exchange between the cell and its environment is essential.
HARD
AS and A Level
IMPORTANT
Calculate the surface area, volume and surface area to volume ratio of each of the cubes.
HARD
AS and A Level
IMPORTANT
The fact that the surface area to volume ratio decreases with the increasing size is also true for whole organisms. Explain the relevance of this for transport systems within organisms.
MEDIUM
AS and A Level
IMPORTANT
In Figure 'b', the system has come into equilibrium, so there is no net movement of water molecules. What can you say about the water potentials of the two solutions A and B?
EASY
AS and A Level
IMPORTANT
Why can plasmolysis not take place in animal cells?
HARD
AS and A Level
IMPORTANT
There are more mitochondria than average in pancreatic acinar cells. Suggest a reason for this.
EASY
AS and A Level
IMPORTANT
What are the most abundant molecules in the cell surface membranes of plant cells?
EASY
AS and A Level
IMPORTANT
Where are the carbohydrate portions of glycolipid and glycoproteins located in the cell surface membrane?
