Ap Bio Lab One: Osmosis and Diffusion

Meghann Kiphart AP Biology Lab overlay Number One Mrs. Irvine Introduction Because every(prenominal) molecules have ki webic energy and ar constantly in motion cubicles go with a process called diffusion. spreading is the endurement if molecules from an atomic number 18a of luxuriouslyer submergence to and argona of lower concentration. This process with bear on to occur until an equilibrium is r all(prenominal)ed. Osmosis is a contrasting and unique kind of diffusion. Osmosis is the diffusion of wet through a perme suit able tissue layer. The explicate permeable membrane means that the membrane forget only allow particularised molecules through such a piss or oxygen.In Osmosis peeing governing body will traveling from an area of higher irrigate likely or an area of lower piss authorization. Hypothesis I think that in this lab, osmosis and diffusion will occur in the midst of the issues of diametric concentrations until a equilibrium is r from each o hav e and thither is no movement of weewee. Materials exemplar 1A dispersion The materials include a 30-cm piece of 2. 5-cm dialysis provide, 15-mL of the 15% glucose/1% amylum ancestor, 250-mL beaker, distilled peeing, 4-mL Lugols termination, and string. EXERCISE 1B Osmosis The materials used include 25-mL of these resolutenesss distilled irrigate, 0. M saccharose, 0. 4M sucrose, 0. 6M sucrose, 0. 8M sucrose, and 1. 0M sucrose, scissors, string, a balance, 6 250-mL instills, and sextette 30cm strips of dialysis tubing. EXERCISE 1C pee Potential The materials that were used included 50mL of distilled urine, 0. 2M sucrose, 0. 4M sucrose, 0. 6M sucrose, 0. 8M sucrose, and 1. 0M sucrose, six 250mL transfuses with lids, 4 white potato cores for each loving cup, a balance, and paper towel. EXERCISE 1D Calculation of piddle Potential from Experimental Data This shape requi inflamed a calculator and a pencil. Procedure EXERCISE 1ASoak the dialysis tubing in pee before you dent the experiment. Tie off one mop up of the tubing to form a pop like structure. Through the open break of the bad, place the starch solving in to the grasp. Tie off the other break off of the nucleotide to secure the substance inside. hold up sure to record the glossary of the solution in tabularise 1. 1. Next youre going to text the starch solution for the presence of glucose. constitution the results in remand 1. 1. Fill a 250ml cup close to 2/3 of the way overflowing with distilled piss system. Add 4ml of Lugols solution into the distilled wet. say the color of the solution in the put off 1. . come in the traction in the cup full of the solution. Allow the stand and cup to stand over night. The undermentioned daytime record the concluding color of the solution in Table 1. 1. Finally discharge the liquid in the cup and in the notecase for the presence of glucose. Record the final results in Table 1. 1. EXERCISE 1B film six strips of presoaked dialy sis tubing and create a bag like was shown in compute 1A. pepper 25mL of the six solutions into each of the six bags. Tie off the other determination of the bags. Rinse each bag thinly with distilled water and dry the revealside of the bag with a paper towel.Weigh each bag and record the results in Table 1. 2. Put each of the six bags into the cups with the six different solutions. Let stand over night. The next day remove the bags from the water and conservatively dry the bags with paper towel. Weigh each bag and record them in Table 1. 2. Gather the other lab pigeonholings info to be able to complete Table 1. 3. EXERCISE 1C Pour 50mL of the solutions into a labeled 250mL cups. Using a cork borer, cut the potato into 24 cylinders. (4 potato cores x 6 cups = 24 potato cores altogether) consult the visual sense of each set of 4 potato cores.Record the information in Table 1. 4. Put 4 potato cores into each solution cup. silver screen the cup with a lid to nix evaporation . Let stand overnight. Remove cores from the cup and dry them with a paper towel. consequently decide in that location combined weigh in groups of 4 (from the same cup). Record the results in Table 1. 4. enumerate the portionages tacks in mass. Collect the class data and determine the class change in mass. prove 1D Determine the solute, pressure, and the water potential of the sucrose solution. Then, graph the information that is given just about the zucchini cores. QuestionsEXPERIMENT 1A 1. Which substances are debut the bag and which are leaving the bag? What evidence supports the answer? Distilled water and IKI are leaving and entering. Glucose is able to sidetrack the bag. 2. formulate the results that were obtained. Include the concentration differences and membrane condense size in the discussion. Glucose and small molecules were able to move through the pores. Water and IKI travel from high to low concentration. 3. How could this experiment be modified so that qua ntitative data could be collected to show that water diffused into the dialysis bag?You could mass the bag before and after it is placed into the solution. 4. ground on your observations, rank the following by relative size, beginning with the smallest glucose molecules, water molecules, IKI molecules, membrane pores, and starch molecules. Water molecules, IKI molecules, Glucose molecules, membrane pores, and starch molecules. 5. what results would you expect if the experiment started with a glucose and IKI solution inside the bag and only starch and water outside? The glucose and IKI would move out of the bag and turn the starch and water solution purple/ blue.The starch couldnt move inside the bag because its molecules are withal big to pass through the membrane of the tubing. EXERCISE 1B 1. Explain the alliance among the change in mass and the molarity of sucrose within the dialysis bags. The solute in hypertonic and water will move into the bag. As the molarity outgrowths t he water moves into the bag. 2. portend what would happen to the mass of each bag in the experiment of all the bags were places in a 0. 4M sucrose solution preferably of distilled water. With the 0. 2M bag, the water would move out. With the 0. M bag, there will be no net movement of water because the solutions reach equilibrium. With the 0. 6M-1. 0M bags the water would move into the bags. 3. Why did you calculate the percent change in mass instead therefore simply using the change in mass? This was calculated because each group began with different sign batch and we would have different data. All the groups need consistent data. 4. A dialysis bag is make full with distilled water and then places in a sucrose solution. The bags initial mass is 20g and its final mass is 18g. Calculate the percent change of mass, showing your calculations. 18-20)/20) x 100 = 10% 5. The sucrose solution in the cup would have been hypotonic to the distilled water in the bag. EXPERIMENT 1D 1. If the potato core is allowed to dehydrate by sitting in the open air, would the water potential of the potato cells decrease or increase? Why? It would decrease because the water would leave the cells and cause the water potential to go down(a). 2. If a plant cell has a lower water potential then its surrounding environment and if pressure is fitting to zero, is the cell hypertonic or hypotonic to its environment?Will the cell kick upstairs water or lose water? It is hypotonic and it will gain water. 3. The cup is open to the atmosphere, what is the pressure potential of the system? The pressure potential is zero. 4. Where is the greatest water potential? In the dialysis bag. 5. Water will diffuse out of the bag. Why? It is because the water moves from the area of high water potential to an area of lower water potential. 6. What government issue does adding solute have on the solute potential dowry of the solution? Why? It makes it more disallow 7.Consider what would happen to a red rootage sell placed in distilled water A) which would have the higher concentration of water molecules? Distilled Water B) which would have the higher water potential? Distilled Water C) what would happen to the red blood cell? Why? It would leak, because it would deal out to much water. Conclusion In cypher 1A the data collected helped tell which molecules tail end and can not move crosswise a cell membrane. IKI, we know because of its color change, was able to move crossways a membrane. Starch, although, is too large to move across a membrane.Glucose was able to move freely, on with the water, across the cell membrane. In 1B, it was be that water moves faster across the cell membrane then sucrose. The water move to help reach equilibrium between the 2 solutions. The sucrose molecules are too big to move across the membrane as fast as water can. In experiment 1C showed that the potatoes contained sucrose. The sucrose in the potato raised the solute potential, which lo wered the water potential. The cup of distilled water had a high water potential water moves down the concentration gradient, causing the potato cores to carry away on water.