Potato Osmosis Lab Report

I know that osmosis will occur in the vegetables, but I am not sure of

Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities.

The Osmosis and Diffusion lab was conducted to provide us with information on how built up mucus affects those conflicted by the recessive genetic disease, Cystic Fibrosis., due to a mutation to the membrane regulating chloride (Cl-). This mutation prevents the Cl- from leaving the cell causing the amount of sodium (Na+) in epithelial cells, which results in extreme mucus on the lungs and airways causing this disease to be fatal if not treated but treatment does not equate to a long lifetime. During the lab we took the data from three parts: Diffusion, Osmosis in an Elodea Cell, and finally the Role of Osmosis in Cystic Fibrosis. During Part 1 we looked at diffusion across a semipermeable membrane for starch and glucose, which resulted in both having a negative solution when placed in a semipermeable membrane. Then we looked at osmosis in the Elodea Cell to watch for the occurrence of Plasmolysis, when a cell’s plasma membrane pulls away from the cell, and how a plant cell is affected by both hypertonic and hypotonic solutions. Finally, we observed the role of Osmosis in Cystic Fibrosis using dialysis bags to represent a normal cell and a Cystic Fibrosis cell with the normal containing 1% NaCl while the Cystic Fibrosis bag contained 10% NaCl. After we ran the experiment, we looked at the Percent Change in Mass and compared them after 30 minutes. We found that Cystic Fibrosis cells didn’t change mass as much as the normal cell ending with a change in mass over -1%. The

The lab for this paper was conducted for the topic of osmosis, the movement of water from high to low concentration. Five artificial cells were created, each being filled with different concentrated solutions of sucrose. These artificial cells were placed in hypertonic, hypotonic, or isotonic solutions for a period of 90 min. Over time, the rate of osmosis was measured by calculating the weight of each artificial cell on given intervals (every 10 minutes). The resulting weights were recorded and the data was graphed. We then could draw conclusions on the lab.

There are 3 potential states that the cell could be in depending on the type of solution:

The difference is that along with large molecules, living cells prevent molecules with positive charges and solubility. This is not representing in dialysis tubing, and is only found in living cells because the tubing is only based on molecular size (98). When referring the rate of diffusion, the concentration gradient influences the diffusion rate, based on the factors of temperature. The ability for molecules diffuse from high to low concentrations primarily depends on the concentration gradient between the two areas.(96-99). My hypothesis for the study is that in the hypotonic, hypertonic, and isotonic solutions, the direction and rate of osmosis will determine based on the concentration inside the dialysis tubing. My prediction is that if the solution is hypotonic the results will decrease, if the solution is hypertonic the results will increase and if the solution is isotonic the solution will vary and or remain constant.

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

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.

The aim of the sixteenth of November experiments was to observe how three different solutions with various sucrose concentration influenced osmosis in relation to three onion cells and the impact on the cells structure.

Activity 3: Osmosis Osmosis is a specific type of diffusion. It is the movement of water molecules from an area of high water concentration to an area of low water concentration. Semipermeable membranes, such as the cell membrane, allow the unrestricted movement of water across the membrane, at the same time restricting the movement of solute molecules and ions. It has been estimated that an amount of water roughly equivalent to 250 times the volume of the cell diffuses across the red blood cell membrane every second. Despite this large movement of water molecules, the cell does not lose or gain water, because equal amounts go in and out.

The purpose of methodology is to maintain the most accurate results by conserving the temperatures of each sample of potato. By wrapping the potatoes in tin foil, it not only maintains the heat of each, but it also allows them to have close to almost the same temperature with each other when they are trapped with the same heat. This makes sure that the hot potatoes do lose their heat and that the cold potatoes remain cold. Maintaining the same temperature for each potato prevents the results of the trials for the same potato from being different from one another. The control group consists of having the same type of potato, washing all the potatoes in the same water to get rid of grime, having about the same sized potato pieces, using 150 mL

The Graphs below show the percent changes in mass for both the class averages and our group's averages:

The purpose of this experiment was to investigate the effect of the change in concentration of sucrose on the rate of osmosis in cylinders of potatoes.

will never be the same weight as we had to cut them ourselves and it

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