## The semi-permeable membrane from an area of

The
purpose of the experiment, which was determining the solute concentration of a
potato, was found by observing and measuring the quantitively results of the
water flow from the solution to the potato. The process observed is called
osmosis, a passive transport method in which water diffuses across a semi-permeable
membrane from an area of a low solute concentration to an area of high solute
concentration. By doing this, a relation can be formed between the solute
concentration of the solution and the percent change in mass. This relation can
be used to create a graph that shows the trends of between the two and
therefore, allow a conclusion to be drawn from the data. With the graph (refer
to figure one), the value of the x-intercept of the line of best fit will be the
sucrose concentration, as a zero percent change in mass would tell us that
there was no net movement of water. Based on the results obtained, the sucrose
concentration of the potato was approximately 0.3113 M.This
experiment was meant to emphasize the process of osmosis and the concept of
zero net movement in an isotonic solution. A solution can be declared isotonic
when there is an equal amount of solute inside and outside of the cell (citation).
This also means that the solution has reached an equilibrium. To further build
upon this concept, reaching an equilibrium would result in the mass of the cell
to being the same as before. In the experiment, reaching an equilibrium would
result in the mass of the potato being the same before and after submersion in the
solute concentration solutions.

With
osmosis, three different results can occur, a hypertonic, hypotonic, and
isotonic solution, one of which will yield the concentration of the potato. With
the results, it would tell you different changes that had happened to the water
and potato during the elapsed time. After the potatoes have been submerged for
an elapsed time, a mass increase would indicate that water has moved into the
potato, further revealing that the concentration of the solute of the potato is
higher than that of the solution. This is a hypotonic solution that can be
observed from the graph at solute concentrations of 0.0M and 0.2M (refer to
Figure 1).  A mass decrease would
indicate that water moved to the solution from the potato, revealing that the
solute concentration of the potato is lower than that of the solution. This is
a hypertonic solution can be seen in our results graph at concentrations 0.4M,
0.6M, 0.8M, and 1.0M (refer to Figure 1). Finally, no change in mass would
indicate that there was no net movement within the solutions, revealing that
the solute of the potato to be the same as the solute concentration of the
solution. The movement of water occurs to maintain a balance on both sides of
the semi-permeable membrane of the potato (citation).

As
the solute concentration of the potato was determined to be 0.3113 M, this would
mean that the sucrose concentration solution of this exact molarity, does not
move across the semi-permeable membrane, as equilibrium has already been
achieved. The solution can be labelled as isotonic, further indicating that there
would not be a change in mass, as there is an equivalent sucrose concentration
on both sides of the membrane of the potato.

The data obtained from the experiment yielded a R2
value of 0.9647, suggesting the results obtained from the experiment were quite
accurate and reasonable as the data gathered fits appropriately into the
relationship that is formed between the solute concentration of sucrose and the
percent change in mass. The trend found fits into the data that was obtained
during the procedure, which allows us to acquire our solute concentration of
the potato by interpolation with little uncertainty.

Based
off the results of other experiments that were conducted, the results that were
gathered were comparable to those of the other experiments as the outcomes were
all in a similar range of concentrations. In “Biology Potato Solute
Concentration Lab,” the results obtained are relatively close to the concentration
of 0.3113M that was retrieved from this experiment (cite krista’s lab). As the
values of the concentration are similar, this would indicate that the potato
solute concentration of the experiment is accurate and reasonable.

The
experiment generated reasonable and valid results, making this experiment a
success, however, there are limitations and sources of error that need to be
taken into consideration. There were some limitations regarding the equipment
used, as with the electronic balances and measuring apparatuses, they can only
measure to a certain degree of accuracy that may have resulted in a minor
deviation when calculating the percent change in mass. Another factor that may
have effected our end results were the use of two different potatoes during the
experiment. During the experiment, there was an insufficient amount of area
that could be bored in a single potato enough for three trials of each
concentration solution, therefore, another potato was needed to create enough
pieces for multiple trials of the experiment. Although this may have resulted in
variations in the results, it was necessary to have multiple trials to increase
the accuracy of the overall experiment.

Despite
there being multiple limitations and sources for error, they had such little effect
on the overall procedure, that they did not affect the accuracy and overall validity
of the concentration that was obtained.

This
information can be useful for a variety of applications such as in basic
household applications like cooking and in industrial uses in the agriculture
sector. As seen in the experiment, the higher solute concentration the solution
was, the more dehydrated the potato became as the water inside of the potato
would travel to the other side of the semi-permeable membrane and into the sucrose
concentration solution. This process leaves the sugar, starch, left in the
potato as we know starch is unable to pass through the membrane due to its large
size as a polysaccharide (source). This can create a sweeter potato for cooking
practices if needed, as leaving a potato in water before cooking increases the
sucrose concentration.

As
previously mentioned above, aside from the isotonic solution that were present,
there were also hypertonic and hypotonic solutions in the experiment. In a
hypertonic solution, the potato would shrink in size, as the solute
concentration in the cell is lower than that outside of the cell, causing water
to diffuse out of the cell. The opposite occurs in a hypotonic solution, as the
potato would grow in size, as the solute concentration in the cell is higher
than the solution outside of the cell, causing water to diffuse into the cell. This
information may be deemed useful to those in the agricultural industry, as it
allows them to determine the proper conditions and environments in which their
agriculture grows in. Based on the experiment, growing a potato in a hypertonic
or hypotonic solution could cause the potato to either shrivel and lose out on
its nutrients, or swell up with water, neither of which would be ideal
conditions for growing food.