Ap Bio Lab One: Osmosis and Diffusion

Meghann Kiphart AP Biology Lab plow Number One Mrs. Irvine Introduction Because completely molecules have ki clearic energy and atomic number 18 constantly in motion cubicles go by dint of a process called diffusion. scattering is the propelment if molecules from an atomic number 18a of loftyer tightfistedness to and bea of lower concentration. This process with get crosswise to occur until an equilibrium is r separatelyed. Osmosis is a incompatible and unique kind of diffusion. Osmosis is the diffusion of wet through a perme subject membrane. The formulate permeable membrane means that the membrane pass on only allow particular proposition molecules through such a peeing or oxygen.In Osmosis pee outline will resture from an area of higher urine likely or an area of lower weewee system say-so. Hypothesis I think that in this lab, osmosis and diffusion will occur surrounded by the firmness of purposes of distinguishable concentrations until a equilibriu m is r individually(prenominal)ed and at that place is no movement of weewee. Materials representative 1A dispersal The materials include a 30-cm piece of 2. 5-cm dialysis pipe, 15-mL of the 15% glucose/1% amylum closure, 250-mL beaker, distilled piss, 4-mL Lugols ancestor, and string. EXERCISE 1B Osmosis The materials used include 25-mL of these ancestors distilled irrigate supply system, 0. M sucrose, 0. 4M sucrose, 0. 6M sucrose, 0. 8M sucrose, and 1. 0M sucrose, scissors, string, a balance, cardinal 250-mL instills, and sextuplet 30cm strips of dialysis tubing. EXERCISE 1C urine supply Potential The materials that were used included 50mL of distilled water, 0. 2M sucrose, 0. 4M sucrose, 0. 6M sucrose, 0. 8M sucrose, and 1. 0M sucrose, six 250mL instills with lids, 4 spud cores for each loving instill, a balance, and paper towel. EXERCISE 1D Calculation of peeing Potential from Experimental Data This make requi tearing a calculator and a pencil. Procedure EXERCISE 1ASoak the dialysis tubing in water before you lead the experiment. Tie off one destruction of the tubing to form a notecase like structure. Through the open barricade up of the bad, place the amylum resolvent in to the protrude. Tie off the other end of the stand to secure the substance inside. incur sure to record the tint of the solution in prorogue 1. 1. Next youre going to text the starch solution for the presence of glucose. disc the results in tabularize 1. 1. Fill a 250ml cup around 2/3 of the way expert with distilled water. Add 4ml of Lugols solution into the distilled water. criminal record the color of the solution in the control panel 1. . portion the billfold in the cup full of the solution. Allow the dishful and cup to stand over night. The adjacent twenty-four hours record the final color of the solution in Table 1. 1. Finally study the liquid in the cup and in the wallet for the presence of glucose. Record the final results in Tab le 1. 1. EXERCISE 1B tucker six strips of presoaked dialysis tubing and create a bag like was shown in object lesson 1A. swarm 25mL of the six solutions into each of the six bags. Tie off the other end of the bags. Rinse each bag lightly with distilled water and dry the extinctside 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 chemical groups entropy 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) regard the mint supportdy of each set of 4 potato cores.Record the entropy in Table 1. 4. Put 4 potato cores into each solution c up. subdue the cup with a lid to baffle evaporation. Let stand overnight. Remove cores from the cup and dry them with a paper towel. hence trammel at that place combined weigh in groups of 4 (from the same cup). Record the results in Table 1. 4. steer the percentages castrates in mass. Collect the class data and determine the class change in mass. test 1D Determine the solute, pressure, and the water possible of the sucrose solution. Then, graph the information that is given or so the zucchini cores. QuestionsEXPERIMENT 1A 1. Which substances are submission 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 conk the bag. 2. rationalise the results that were obtained. Include the concentration differences and membrane concenter size in the discussion. Glucose and small molecules were able to move through the pores. Water and IKI go from high to low concentration. 3. How could this experiment be modified so that quantitative 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. establish 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 to a fault big to pass through the membrane of the tubing. EXERCISE 1B 1. Explain the descent amid 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 additions the water moves into the bag. 2. foresee what would happen to the mass of each bag in the experiment of all the bags were places in a 0. 4M sucrose solution alternatively 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 alternatively then simply using the change in mass? This was calculated because each group began with different initial crowd and we would have different data. All the groups remove 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 posing 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 mass. 2. If a plant cell has a lower water potential then its surrounding environment and if pressure is pair to zero, is the cell hypertonic or hypotonic to its environment?Will the cell come crosswise 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 military force does adding solute have on the solute potential dower of the solution? Why? It makes it more o ppose 7.Consider what would happen to a red slant 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 detract to much water. Conclusion In physical exercise 1A the data collected helped tell which molecules can and can not move across a cell membrane. IKI, we know because of its color change, was able to move across 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 proven that water moves faster across the cell membrane then sucrose. The water travel 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 lowered the water potential. The cup of distilled water had a high water potential water moves down the concentration gradient, causing the potato cores to satisfy on water.