Which Sugar Concentration Osmosis Best Takes Place on a Potato Chip
I am going to conduct an investigation to find out at which sugar
concentration osmosis best takes place on a potato chip.
Osmosis is defined as the net movement of water or any other solution
with molecules from a region in which they are highly concentrated to
a region in which they are less concentrated. This movement must take
place across a partially permeable membrane such as a cell wall, which
lets smaller molecules such as water through but does not allow bigger
molecules to pass through. The molecules will continue to diffuse
until the area in which the molecules are found reaches a state of
equilibrium, meaning that the molecules are randomly distributed
throughout an object, with no area having a higher or lower
concentration than any other.
Membranes are very thin sheets of material which surround living
cells. For example, thin cellophane is a membrane. They have tiny
holes in them to allow small particles to get through. Particles like
water molecules can get through easily; however, larger molecules such
as starch cannot. If a membrane separates a strong and a week
solution, the water molecules will pass through the membrane until
each solution is of equal strength.
Some Information on Plant Cells:
Plant cells always have a strong cell wall surrounding them. When they
take up water by osmosis they start to swell, but the cell wall
prevents them from bursting. Plant cells become "turgid" when they are
put in dilute solutions. Turgid means swollen and hard. The pressure
inside the cell rises and eventually the internal pressure of the cell
is so high that no more water can enter the cell. This liquid or
hydrostatic pressure works against osmosis. Turgidity is very
important to plants because this is what make the green parts of the
plant "stand up" into the sunlight.
When plant cells are placed in concentrated sugar solutions they lose
water by osmosis and they become "flaccid." This is the exact opposite
of "turgid". The contents of the potato cells shrink and pull away
from the cell wall. These cells are said to be plasmolysed.
When plant cells are placed in a solution which has exactly the same
osmotic strength as the cells they are in a state between turgidity
and flaccidity. We call this incipient plasmolysis. "Incipient" means
"about to be".
My aim is to investigate the effect of varying concentrations of a
certain sugar solution on the amount of osmotic activity between the
solution and a potato chip of a given mass.
Variables are the things that we are going to change during the
investigation, and are things which will affect the experiment on the
whole. One of the variables will be the concentration of sugar in the
solution. This will...