Potato Core Lab

After 48 hours, remove each set of three cores from their containers. dry them with a paper towel to remove excess water. find mass of all 5 potato cores, record the mass in the data table.

My prediction is that as the concentration increases, the potato cell will lose more weight. This is because of the osmosis of water particles from the potato cell cytoplasm to the solution, resulting in a loss of weight. As the concentration decreases, the potato will lose less weight until a certain point where the osmosis of particles in and out of the potato cells will be equal. I also predict that as the salt

As the Concentration of the Sucrose Solution decreases, the more the potato’s mass increases. This is due to the solution being hypertonic. So, as the solute concentration gets lower, the potato’s water concentration will get higher, therefore more water particles from the solution will absorbed by the potato. Some changed very little in mass because the concentrations of the H2O molecules in the potato and outside the potato were equal. This equality in concentration is called Isotonic.

Van’t Hoff’s Law suggests that the osmotic potential of a cell is proportional to the concentration of solute particles in a solution. The purpose of this experiment was to determine if there are any differences between the osmolalities, the no-weight-changes of osmolalities, and the water potentials of potato cores in different solutions of different solutes. The percent weight change of the potato cores was calculated through a “change in weight” method. The potato core’s weight was measured before and after they were put into different concentrations of a solute for 1.5 hours. In our experiment, there were no significant differences from the osmotic potentials of our results and the osmotic potentials of other scientists work. Ending with chi square values of 2.17 and 2.71, and p values of 0.256 and 0.337, concluding that there is no difference in water potentials of potato cores in different solutions of different solutes at varying concentrations.

However one beaker received 100 mL of Deionized water with a molarity of 0.0. Afterwards a cork borer was pushed through the potato and was twisted back and forth. Once the borer was filled it was removed from the potato. Pushing the potato cylinder out of the borer, this this step was repeated six more times in order to get seven undamaged potato cylinders. Using a sharp razor blade, the potato cylinders were both cut to a uniform length of about 5cm, and were removed of their potato skins. The potato pieces were also cut in half to give the cells a greater surface area in which it was easier to absorb the solution. After the cylinders were weighed on a balance and the data was recorded in Table 4. Using the razor blade each potato was cut lengthwise into two long halves. Then the potato pieces were transferred to the water beaker and the time they were submerged was recorded. This step was repeated for all potato cylinders in which the pieces were placed in solutions 0.1 to 0.6 M. The potatoes were incubated for ninety minutes. At the end of the incubation period the time was recorded. Then the potato piece was removed form the first sample. Next potato pieces were weighed the and the final weight was recorded in Table 4. This procedure was repeated until all samples had been weighed and recorded in the chronological order they were initially placed in the test solution. Afterwards the table was completed by recording the

Either the solution is hypotonic which means that the solution has a lower concentration than the potato core and this would cause water to flow into the potato and make it larger and therefore increase its mass. The state the cell is in is called turgid.

When the final mass was measured the excess water in the potato cube might have not been completely removed, thus it adds to the final mass of the potato cubes. This acts as a major error because it gives an inaccurate representation of the actual percentage change in mass of the potato cubes, also while measuring the mass of each cube of potato; the value fluctuated and was not consistent.

In conclusion when the molarity level was at 0 and at .2 the potatoes had gained mass so therefore they were placed in a hypotonic environments. When the molarity level was .4 and above the potatoes loss mass so therefore they were placed in hypertonic environments. So the different in concentrations does change the mass of the potatoes because they determine the osmosis environments.

Data: Effect of Solute Concentration on Osmosis in Potato Cells (for the 6 groups of our class)

Once the hour was over, the potato slices were removed from the solution, dried off in a paper towel, and weighed once again. In the 0.0, 0.1, and 0.2 M of sucrose concentrations the final mass of the potato increased. Therefore H2O enters the potato cell because the solution is hypotonic. In the 0.3, 0.4, and 0.5 M of sucrose concentration the final mass of potato decreases. The solution is hypertonic which causes H2O to exit the potato cells through the semipermeable phospholipid bilayer. The results prove that the different molarities of concentration affect the mass of the potato in different ways; the mass of potato either increased or decreased depending on the molarity of sucrose concentration.

MATERIALS 8 potato slices 4 Beakers Timer 4 concentrations of solutions of salt (NaCl) dissolved in water: 100 mL of each per group 0% - pured distilled water 5%- 5 NaCl/100g solution 10%- 10g NaCl/100g solution 15%- 15g NaCl/100g solution Balance Paper Towel Graduated Cylinder PROCEDURE Weigh the potatoes and make observations Record the initial observations and beginning masses in the tables Label beakers by the percentage of the salt: 0%, 5%, 10%, 15% Put 100 mL of the solutions in the correctly labeled beakers Put 2 Potatoes in each solution Pat dry potato and weigh the Potatoes (After 30 minutes) Make final observations and record the ending mass in the table Calculate percent change (final - initial)/initial x 100 for each potato DATA Type of Salt Solution Beginning Observation

The potato cells, took in, or gave out the water depending on the concentration of the solution it is surrounded in. The results were fine and by looking at the mass measured before the experiment, you can see that there is no reading which seems to be out of the line. As the weights before the experiment range between 2.31g and 2.46g, this tells us that the potato pieces were cut well, and I believe accurate enough. The results show that: - Osmosis actually took place in the experiment.

In this lab we are going to discovery how osmosis works using a semi-impermeable membrane a potato slice. Osmosis is known as the movement of water in and out of a cell. To understand how this works we must understand two terms. Hypotonic means the environment has less solutes compared to the inside of the cell. Hypertonic means that the environment has more solutes compared to the inside of the cell. With osmosis water will always move from hypotonic too hypertonic. So the question is will water move into the potato or out of the potato? Will these results change when placed in different morality of salt water? To calculate these results, we will measure the mass of potatoes cut into equal sizes then soak these potato slices in different morality of NaCl for thirty minutes and measure the mass change in each potato slice.

I recorded the difference between the 600 ml and the measure of ml that the water raised after I put the sweet potato in, 870ml. I calculated the density by dividing the weight of the potato in grams by the ml that the sweet potato was. I used a device to convert the .2 pounds into grams. The equation looked like this: 90.7185gm / 270ml = .33599444

The independent variable of this experiment were the different types of the solutions used, while the dependent variable was the mass of the cucumber slices. The constants were, the amount of liquid used and the time the cucumbers were left in the solution. While the control was the cucumber left in the cup with no solution. The students made a hypothesis saying that they believe that the cucumber slices put into the salt solution would decrease in mass while the cucumber put in the distilled water would increase in mass. In the end, the results of the experiment supported the students