Potato Toys Lab Report

Figure 1: Percentage change in potato tuber mass vs. sucrose concentration. The percent change in mass decreased as the sucrose concentration increased. Relative osmotic concentration was measured as the percent change in mass of sucrose concentration over one hour.

Trim the skin off with a knife (Try to make them all the same width.)

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

2) When the concentration was at 0.3M, the potato’s cytoplasm and the sucrose solution was isotonic. The concentration of the potato’s cytoplasm was having the same solute concentration as the surroundings. Therefore, there would be no net movement of materials happening.

Though the theory following the hypothesis is correct and the experiment was carried out with as much attention as possible in a high school laboratory, the results obtained were still indicative of a few errors and did not support the predicted hypothesis. From the results obtained it can be concluded that as the concentration of sucrose increases the average percentage change in mass decreases. This is because the salt concentration inside the potato cubes of 10%, 15% and 20% concentration is less that in the salt concentration on the sucrose solution, thus the three cubes submerged in the 10% - 20% concentrated solution lost mass (hypertonic). However the cube submerged

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.

This was due to the water moving out of the core’s cells to maintain homeostasis using osmosis (diffusion of water across the cell membrane). The solutions with the concentrations of 0.0 M, 0.1 M, 0.15 M, and 0.2 M were hypotonic (meaning that the concentration of solutes inside the cell was higher than the concentration outside of the cell) so the mass of those potato cores increased since water moved into the potato cores using the process of

Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is

Foor this you simply have to take a look at the processed data table and graph. There is a clear specific trend, visibly recognizable as well as mathematically (a trend line indicates it), that is, as the molar concentration (solute) of salt increased in the solution where potatoes were placed, the mass of potatoes decreased. Now, from the molar concentrations of salt solute that we tested (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1.0M) we cannot decipher with certainty and accuracy what is the molar concentration of potato cells. However, we can estimate, and judging by the a decrease in percent mass from 21.10% grams (0.0M) to 12.13% (0.2M) and followed by a constant decrease in percent change in mass, it can be said that the salt concentration of a potato cell is between 0.0M and 0.2M. This is because these molar concentrations are the one that show the decrease in mass of the potato. When there’s a decrease in mass, this practically means that the water inside the cells is leaving because of diffusion to areas of lower concentration.

If the C.melo is put in the lowest sucrose concentration, then it will cause an increase in mass because the water molecules pass from an area of high water potential, although the water itself, to an are of low water potential in the C.melo. As a result of this, the C.melo in the concentrations of sucrose with a lower water potential will reduce the initial mass as the water potential is higher inside of the C.melo, than in the sugar concentrations. The “net movement” (in the direction of increased concentrations) of the water molecules is into the cell, and the cell will increase in mass.

As we can see in Figure’s 1.2 and 1.3, when there was no sucrose solution, the potato increased in weight. This is due to the fact that the sucrose solution was hypertonic in comparison to the potato slice. Through osmosis, the solution moved along the concentration gradient and into the potato slice making it hypotonic. When there were higher concentrations of sucrose solution, the potato decreased in weight. This is due to the fact that the potato was hypertonic in comparison to the potato. Through osmosis, sucrose from the potato moved along the concentration gradient out and into

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.

The Purpose of the Potato Lab was to see how salt water will affect your cells. The example used was, if a person was stranded in the middle of the ocean with no fresh water, would the salt water hydrate them? Since using human cells wasn’t an option, the lab called for potatoes to replicate what would happen to human cells. The potatoes were placed in water beakers, one with salt and one with no salt, to see how the potatoes would be affected by the two different solutions. The two different solutions were hypertonic, and hypotonic. Hypotonic solutions are solutions that have a higher percentage of water molecules to other solutes in the solvent. Hypertonic solutions are solutions that have a lower percentage of solutes in the solvent than water in the solvent. These solutions are a major part in osmosis. Osmosis is a process in which one side of a solution is separated from the other side with a permeable membrane, if one side has a higher concentration of molecules, the molecules will shift over to the side with less molecules to create

If the solution contains only sucrose then the osmotic pressure will increase substantially. This would represent a hypotonic solution because more water molecules are entering the cell meaning the solution contains no invertase. If the osmotic pressure has a slight increase than the solution contains sucrose and invertase due to the rate of the sucrose being broken down, however the cell will overtime begin to shrink. If the osmotic pressure remains close to the same than the solution contains no sucrose, containing only water and invertase. We predicted that because the height of the fluid in the osmometer tubing was increasing only a little bit our blue solution was hypertonic and contained invertase and sucrose. The invertase was able to break down sucrose into glucose and fructose which were small enough to be able to leave the cell membrane. This would reflect a hypertonic solution. We predicted this would cause the cell to shrink in size and the height of the fluid would never increase.

out the potato and dry it to ensure excess water is not added to the