Rate of Osmosis Between Potato Cylinders and Sucrose Solution
I am doing an investigation, to find out on how varying one factor
effects the rate of osmosis between potato cylinders and Sucrose
Osmosis is the diffusion of solvent (usually water) particles through
a selectively permeable membrane from a region of high solvent
concentration to a region of lower solvent concentration.
Examples of Selectively permeable membranes are (a) the cell membrane,
and (b) visking (dialysis) tubing. Such membranes are thought to have
tiny pores that allow the rapid passage of small water particles, but
restrict the passage of larger solute particles.
Since the membrane is Selectively permeable, Osmosis is important in
the passage of water into and out of cells and organisms, and depends
on Osmotic pressure.
The pressure exerted by the osmotic movement of water that can be
demonstrated in an Osmometer. Water moves into the solution in the
visking bag by Osmosis, causing the liquid level in the tube to rise.
Osmotic pressure depends on the relative solute concentrations of the
solution s involved. The Osmotic pressure that a solution is capable
of developing is called its osmotic potential, but is only realised in
All living things have certain requirements they must satisfy in order
to remain alive. These include exchanging gases (usually CO2 and O2),
taking in water, minerals, and food, and eliminating wastes. These
tasks ultimately occur at the cellular level, and require that
molecules move through the membrane that surrounds the cell. This
membrane is a complex structure that is responsible for separating the
contents of the cell from its surroundings, for controlling the
movement of materials into and out of the cell, and for interacting
with the environment surrounding the cell.
There are two ways that the molecules move through the membrane:
passive transport and active transport. Active transport requires that
the cell use energy that it has obtained from food to move the
molecules (or larger particles) through the cell membrane. Passive
transport does not require such an energy expenditure, and occurs
The principle means of passive transport is diffusion. Diffusion is
the movement of molecules from a region in which they are highly
concentrated to a region in which they are less concentrated.
It depends on the motion of the molecules and continues until the
system in which the molecules are found reaches a state of
equilibrium, which means that the molecules are randomly distributed
throughout the system (the net movement will then therefore be zero).
Osmosis is a special case of diffusion. In this case, sucrose...