Testing The Effect Of Sucrose Concentration On The Rate Of Osmosis

Diffusion is defined as the movement of molecules from an area of high concentration to an area of low concentration. The diffusion of water molecules through a semi-permeable(selectively permeable) membrane is osmosis. Semi-permeable means that some molecules can move through the membrane while others can not. Diffusion and Osmosis are passive forms of transport requiring no energy. Active Transport utilizes energy in the form of ATP. Water is a solvent that can dissolve a number of substances more than any other substance. Wherever water goes, through the ground or a body, it takes along valuable molecules. Water’s chemical composition causes it to be attracted to many different molecules and be attracted so strongly it disrupts the forces and dissolves it. Water can pass through the semipermeable membrane without any help but can change the solution, on the other side of the cell membrane, depending on how much it diffuses in and out.

Part B: How will the molarity of sucrose solution outside the root vegetable affect the percent change in mass of the root vegetable after being left in the solution for about 48 hours?

How do different concentrations of sucrose solutions (0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M) affect the mass of potato cores when in sucrose solution?

In order to test the predictions of the hypotonic, hypertonic, and isotonic hypothesis for the solution  made during the study,  four samples of sucrose were taken and placed into two different beakers each containing a different concentration. Beaker 1 is  250- mL and contained 150-mL of 10% sucrose with dialysis tubing A, while beaker 2 (a large bowl) contained 1% sucrose, with dialysis tubing  B, C, and D. Tubing A contained 10-mL with 1% sucrose. Tubing B

Osmosis is the passive movement of water from an area of low solute concentration to an area of high solute concentration, normally across a membrane which prevents the movement of solvent. This is a process by which materials may move into, out of, or within cells. Osmosis doesn’t depend on energy provided by living organisms but is affected by the properties of the cell membrane. The rate of osmosis is dependent on such factors as temperature, pressure, molecular properties such as size and mass, and the concentration gradient. In osmosis, the relationship between a solute’s concentration outside of cell and inside of a cell is described in terms of the tonicity of the solution outside of the cell. A cell is in a hypotonic solution when the solute is more concentrated inside the cell and therefore water moves into the cell. In this solution the cell swells as water enters, this may continue until it ruptures or hemolyzes. In the reverse condition, the cell is in a hypertonic 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

Part I In procedure A of part I, the celery soaked in saltwater was much more flexible than the celery soaked in distilled water. This was the expected result because when soaked in saltwater, the celery would presumably lose water and water is generally what gives fruits and vegetables their crispness. Of course, malleability of celery is not quantifiable, so it is difficult to say for sure that the flexibility of the celery really changed drastically and that being soaked in the saltwater caused the change. Perhaps, in addition to just observing the celery after soaking it, the experiment would have benefitted from massing the pieces of celery before and after just to be sure that the change in flexibility can be attributed to a gain or

- As the sucrose solution increased, the mass decreased, and as the sucrose solution decreased, the mass increased Evaluation: I followed the plan correctly; I believe I gained accurate and sufficient enough results to conclude the experiment, and to prove my prediction. To make this experiment better, I believe that I could have done more than one experiments to see if anything has gone wrong, but since

Osmosis is a special type of diffusion. It is the diffusion of water across a semipermeable membrane which is a membrane that is freely permeable to water but is not freely permeable to solutes, the water moves from a dilute solution to a more concentrated solution (Karp, 2010). Both diffusion and osmosis are passive transport, energy is not used in the transport. In osmosis water moves across a membrane toward the solution of greater concentration, because the concentration of water is lower there (Martini and Bartholomew., 2007).

The reason I predict that three will increase in mass and two decrease is because in my preliminary experiment this was shown to be the case in these concentrations, however this could change in my real experiment. The chips that increase in mass have taken on more water which means that at the beginning of the experiment the sucrose solution had a higher concentration of water than the chip and this is likely to apply to the weaker sucrose solutions as they have a low concentration of sugar and therefore a high percentage of water molecules. The strong sucrose solutions have a higher percentage of sugar molecules and therefore a lower percentage of water molecules and if the concentration of water in the potato chip is higher than in the solution then water will leave the potato chip by osmosis and therefore the chip will lose mass. The water molecules move into cells that contain a lower concentration due to the difference in osmotic potential between cells.

Osmosis is a form of diffusion; water moves through a selective permeable from an area of its higher concentration to an area of a lower concentration. Also, this osmosis is directed by a solute concentration. In hypotonic solution, the cell gain water to dilute the concentration because the concentration of a substance is larger with in the cell. Whereas, hypertonic solution, the cell lose a water to increase the concentration of the substance because the concentration is larger in the solution than within the cell.

The previous prediction was proven to be correct. The negative line of best fit that was illustrated onto the graph did not go through all of the data points and suggests random error. The point where the line crosses at 0% change in mass at the horizontal axis, the solution of water molecules in the potato cell is equal to the concentration of sucrose. Therefore, the concentration of sucrose is isotonic with the cytoplasm of the potato cylinder. Thus, there is no net movement of water by osmosis

The chart below shows the % change in mass after being in their concentrated solutions:

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

This experiment was used to examine the hypothesis that: Osmosis is dependent on the concentrations of the substances involved.