Bio011L: Molecular Biology Laboratory
Exercise 3 – LAB 3 – Diffusion & Osmosis
PRELAB QUESTIONS
In your own words, please state in one paragraph the purpose of this entire lab?
Not easy to do! (4 points)
The purpose on this lab is to understand the basis of molecular diffusion, while also being able to
represent as to why diffusion is important in life. We will also focus on aspects such as the
process of osmosis and osmotic pressure, hypotonic, hypertonic and isotonic. Lastly we will also
go over how the differences in protein content of membranes lead to the different cell types that
we know of today.
Q1) What force is responsible for diffusion?
There is no force responsible for diffusion, diffusion moves from high concentration to low
concentration
Q2) Osmosis is concerned with the movement of which molecules across semipermeable
membranes?
Osmosis is concerned with the movement of water molecules across semipermeable membranes.
Q3) Which substances are able to diffuse across the lipid region of the cell membrane unaided?
Substances that are able to diffuse across the lipid region of the cell membrane unaided include
small non polar molecules. Examples of these molecules may include carbon dioxide CO2 and
oxygen O2
