Investigating the Water Potential of a Potato

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

Based on the experiment result, it supports my hypothesis that as concentration of sucrose increases the mass of potato will be decrease due to its temper is to make an equivalent concentration between the solution and potato. For instance, in the graph that above shows the first one on x-axis is the highest mass of potato that spent 5 days in distilled water. On the other hand, the fourth one is the lowest mass, which represents 4M sucrose solution of potato. Moreover, the data proves my prediction, as water molecules from higher sucrose solution of potato moves out actively from the potato through semi-permeable membrane into the sucrose solution. In details, the important evidence that supports my hypothesis is then the potato will be shrink

Osmosis is a natural occurrence constantly happening within the cells of all living things. For osmosis to occur, water molecules must move across a semipermeable membrane from an area of low concentration to an are of high concentration. In order to understand osmosis, people must understand the different types of concentrations that can be present within solution. One of them is an Isotonic solution where the concentration of dissolved particles is equal to that of a cell’s. Another is a hypertonic solution where there is a higher concentration of dissolved particles then inside the cell. And lastly there is a hypotonic solution where there are less dissolved particles than inside the cell. As dissolved particles move to a region of lower concentration, water moves the opposite direction as a result of there being less water in the highly concentrated region. In this experiment, gummy bears were placed in salt water, sugar water, and tap water to find the measure of osmosis between the solution and gummy bear.

The main purpose of the experiment was to test the idea that water would move from the higher concentration to the lower concentration. In order to test this theory, we placed potato slices in 7 different containers, each containing different concentrations of NaCl, to measure the weight change from osmosis. The containers ranged from 0M NaCl all the way to .6M NaCl. We measured the potato slices before and after placing the slices in the solutions and recorded the net change in weight to determine the tonicity of the potato cells. Our results showed that the potato slices put in a NaCl solution of .2M or higher lost weight and the potato slices put in a NaCl solution of .1M or lower gained weight. This shows that the osmolarity of the potato falls within the range of .1M to .2M, and it also proves the process of Osmosis by having the higher concentration move to the lower concentration. In addition to this, it can be concluded that the osmolarity of cells can be determined by observing the affects of osmosis.

Osmosis is the diffusion of water across a membrane to create an equilibrium between the levels of concentration of a solute both inside and outside the cell. In this case the solute will be sugar as the potato core will be immersed in sucrose solution.

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

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

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.

In conclusion, the potato cube with the highest surface area to volume ratio (the 1x1x1 cube) had the fastest rate of diffusion as it had the largest percentage increase in mass. While all the other cubes of potato had larger increases in mass at face value compared to the smallest cube, the smallest cube had the largest overall gain in percentage. The results support my hypothesis that the smallest cube will have a higher rate of osmosis because it has a proportionally larger amount of surface area compared to its volume.

Showing an example of diffusion with the water molecules equally back and forth the semi-permeable membrane of the potatoes and the saucer of water. The hypertonic solution of salt water has given an example of osmosis. The water molecules passed through the semi-permeable membrane out of the potatoes but weren’t able to get back in as easily due to the salt blocking the membranes passage. This left the potatoes in the salt water saucer feeling flexible and spongy almost leaving the potato a little

Measure the mass of the sugar cubes, sketch what the cubes look like and record the data.

As suggested by the graph above and the data obtained through the conduction of the experiment, an evident correlation between the surface area to volume ration and the rate of osmosis can be implied. As can be seen from the graph, as the surface area and volume ratio of the cube is increased, the % change in mass is decreased (as suggested by the % change in mass of 2 x 2 x 2 cube). In a contradicting manner, as the SA: V of the potato cube in decreased, the % change in mass of the potato cube in increased (as suggested by the % change in mass of 1 x 1 x 1 cube). This pattern in the data reinforces the hypothesising statement, which stated that “if the size of potato is larger, then the rate of osmosis would be gradual due to its smaller volume to surface area ratio, whereas if the size of the potato is smaller, then the rate of osmosis would be faster.”

Osmosis is the movement of water molecules from high concentration to low concentration through semipermeable membranes, caused by the difference in concentrations on the two sides of a membrane (Rbowen, L.). It occurs in both animals and plants cells. In human bodies, the process of osmosis is primarily found in the kidneys, in the glomerulus. In plants, osmosis is carried out everywhere within the cells of the plant (World Book, 1997). This can be shown by an experiment with potato and glucose/salt solution. The experiment requires putting a piece (or more) of potatoes into glucose or salt solution to see the result of osmosis (a hypertonic type of solution is mostly used as it would give the most prominent visual prove of

The purpose of this lab is to test the effect of osmosis on cucumber slices. If a cucumber slice is placed in a hypertonic solution, then the mass of the cucumber slice will decrease. Whereas, if

The dependant variable will be the mass of the potato as this is the variable I will be measuring. From this I can see the change in mass(g) and so work out the amount of water that has moved and the rate of the osmosis in a