An Inquiry-Based Approach Important:
Which substance s are entering the bag and which are leaving the bag? What experimental evidence supports your answer? Glucose and water left the bag, the evidence was the Testape color. Explain the results you obtained.
Include the concentration differences and membrane pore size in your discussion. The results simply state that the water, glucose, and IKI were small enough molecules to pass through the selectively permeable membrane.
Quantitative data uses numbers to measure observed changes. How could this experiment be modified so that quantitative data could be collected to show that water diffused into the dialysis bag? Quantitative data would include the initial and final percent concentrations of the glucose, therefore showing the concentration of water by the change of percent in glucose.
The movement would be noticeable in the concentration because it is known that water moves from high water potential to a low water potential. Based on your observations, rank the following by relative size, beginning with the smallest: The smallest substance was IKI, followed by water, glucose, the membrane pores, then the starch molecules.
What results would you expect if the experiment started with a glucose and IKI solution inside the bag and only starch and water outside? Based on the size of the molecules, the glucose and IKI would move out of the bag, the water in, and the starch left in the beaker again.
Explain the relationship between the change in mass and the molarity of sucrose within the dialysis bags. These two things are directly proportional. As the mass increases, so does the molarity. Predict what would happen to the mass of each bag in this experiment if all the bags were placed in a 0.
These are inversely proportional because whenever the sucrose molarity inside the bag is more concentrated, it will become more dilute and vise versa. The solutions will reach equilibrium somewhere between the two concentrations.
Why did you calculate the percent change in mass rather than simply using the change in mass? The percent was calculated to give the exact difference, along with considering the quantities of solution. A dialysis bag is filled with distilled water and then placed in a sucrose solution.
Calculate the percent change of mass, showing your calculations in the space below. If a potato is allowed to dehydrate by sitting in the open air, would the water potential of the potato cells decrease or increase?
The water potential of the potato would decrease because water moves from a high water potential region to a low potential region, and a dehydrated potato cell is hypertonic in comparison with the environment, forcing water to come into the cell.
The moving in part shows that the potato cell had a low water potential. If a plant cell has a lower water potential than its surrounding environment, and if pressure is equal to zero, is the cell hypertonic or hypotonic to its environment?
Will the cell gain water or lose water? If the plant cell has lower water potential, that means the water will come into the cell, the cell is hypertonic to its environment.
This cell will gain water because water follows its concentration gradient. What is the pressure potential of the system? The pressure potential in this figure is equal to zero. The greatest water potential is within the dialysis bag. Water will diffuse out of the bag because the highest water potential is inside the bag, forcing the water out.
Calculate solute potential of the sucrose solution in which the mass of the zucchini cores does not change. Calculate the water potential of the solutes within the zucchini cores.Port, diffusion and osmosis describe the movement of molecules.
Biology: Osmosis and Diffusion Lab using Potato Cores. Diffusion lab report, gummy bear diffusion lab report, osmosis and diffusion lab report conclusion, lab report on diffusion and osmosis in elodea, lab report on. Procedure A: Modeling Diffusion and Osmosis There will be five different solutions: M sucrose, M sucrose, M sucrose, M sucrose, M sucrose.
You will not know which solution is which:) Rather, we will use what we know about diffusion and osmosis in . The College Board. Part 2: Modeling diffusion and osmosis-- (note: this is the one he talks about first) Show what a semi-permeable membrane is (iodine moves in but the starch is stuck in the dialysis tube) Part 3: Observing osmosis-- Molarity of sucrose water and potatoes.
This activity could be carried out by students working as individuals or in pairs, depending on the number of microscopes available. Or small groups could use different concentrations of sodium chloride solution, and the . AP Biology Welcome!! AP Summer Assignment Lab Day is Saturday October 27th– Time to be determined by the class.
Campbell Chapters to be read for This is the Link to Tank Test Graph and Table. 12/1– Review of Osmosis and Diffusion Lab.