Ap Bio Lab One: Osmosis and Diffusion

Meghann Kiphart AP Biology Lab Report Number One Mrs. Irvine macrocosm Because all molecules beget kinetic energy and are constantly in motion jail cells go done a process called diffusion. Diffusion is the tendency if molecules from an area of higher meanness to and area of set out concentration. This process with affect to occur until an sense of balance is r apieceed. Osmosis is a different and unique kind of diffusion. Osmosis is the diffusion of body of pee through a permeable membrane. The phrase permeable membrane means that the membrane entrust only allow specific molecules through such a wet or oxygen.In Osmosis wet supply impart start from an area of higher water system potential or an area of let down water potential. Hypothesis I think that in this lab, osmosis and diffusion will occur between the rootages of different concentrations until a equilibrium is r severallyed and there is no terminatement of water. Materials doing 1A Diffusion The mate rials include a 30-cm piece of 2. 5-cm dialysis tubing, 15-mL of the 15% glucose/1% starch ascendent, 250-mL beaker, distilled water, 4-mL Lugols solving, and string. EXERCISE 1B Osmosis The materials use include 25-mL of these solutions distilled water, 0. M saccharose, 0. 4M sucrose, 0. 6M sucrose, 0. 8M sucrose, and 1. 0M sucrose, scissors, string, a balance, half a dozen 250-mL loving cups, and six 30cm strips of dialysis tubing. EXERCISE 1C weewee 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 cups with lids, 4 stump spud cores for each cup, a balance, and composing towel. EXERCISE 1D Calculation of piss Potential from Experimental Data This shape required a calculator and a pencil. Procedure EXERCISE 1A fleece the dialysis tubing in water before you start the test. Tie sour one end of the tubing to form a grasp similar structure. Through the uncovered end of the bad, place the starch solution in to the al-Qaeda. Tie off the different end of the saucer to secure the heart inside. Make sure to record the color of the solution in send back 1. 1. Next youre going to text the starch solution for the aim of glucose. Record the results in card 1. 1. Fill a 250ml cup near 2/3 of the way full with distilled water. Add 4ml of Lugols solution into the distilled water. Record the color of the solution in the Table 1. . Put the dish antenna in the cup full of the solution. Allow the bag and cup to contribute over night. The coterminous day record the final color of the solution in Table 1. 1. Finally test the liquid in the cup and in the bag for the presence of glucose. Record the final results in Table 1. 1. EXERCISE 1B Get six strips of presoaked dialysis tubing and create a bag like was shown in exercise 1A. Pour 25mL of the six solutions into each of the six bags. Tie off the other end of the bags. Rinse each bag gently with d istilled water and dry the outside of the bag with a musical theme towel. beseech 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 re spark the bags from the water and carefully dry the bags with story towel. Weigh each bag and record them in Table 1. 2. Gather the other lab groups data to be able to boom Table 1. 3. EXERCISE 1C Pour 50mL of the solutions into a labeled 250mL cups. Using a cork borer, cut the white potato into 24 cylinders. (4 potato cores x 6 cups = 24 potato cores altogether) weigh the aggregate of each set of 4 potato cores.Record the data in Table 1. 4. Put 4 potato cores into each solution cup. Cover the cup with a lid to oppose evaporation. Let stand overnight. Remove cores from the cup and dry them with a paper towel. Then determine there combined weigh in groups of 4 (from the same cup). Record the results in Table 1. 4. Calculate the percentages falsifys in mass. soak up the class data and determine the class change in mass. experimentation 1D Determine the solute, pressure, and the water potential of the sucrose solution. Then, graph the information that is given(p) about the zucchini cores. QuestionsEXPERIMENT 1A 1. Which substances are entering the bag and which are release the bag? What evidence supports the answer? Distilled water and IKI are leaving and entering. Glucose is able to leave the bag. 2. Explain the results that were obtained. Include the concentration differences and membrane focalise size in the discussion. Glucose and small molecules were able to move through the pores. Water and IKI moved from high to low concentration. 3. How could this experiment be modified so that quantitative data could be collected to show that water distribute into the dialysis bag?You could mass the bag before and after it is placed into the solution. 4. base on your observations, rank the following by relative size, be ginning 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 too big to pass through the membrane of the tubing. EXERCISE 1B 1. Explain the relationship between 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 increases the water moves into the bag. 2. Predict what would happen to the mass of each bag in the experiment of all the bags were places in a 0. 4M sucrose solution instead 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. wherefore did you calculate the percent change in mass rather whence simply using the change in mass? This was calculated because each group began with different initial masses and we would have different data. All the groups need consistent data. 4. A dialysis bag is alter 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 reduce or increase? Why? It would decrease because the water would leave the cells and cause the water potential to go down. 2. If a plant cell has a lower water potential then 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? 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 effect does adding solute have on the solute potential component of the solution? Why? It makes it more negative 7.Consider what would happen to a red occupation 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, beca use it would take to lots water. Conclusion In Exercise 1A the data collected helped tell which molecules hatful and can not move crossways a cell membrane. IKI, we live on because of its color change, was able to move across a membrane. Starch, although, is too tumid to move across a membrane.Glucose was able to move freely, along with the water, across the cell membrane. In 1B, it was proven that water moves faster across the cell membrane then sucrose. The water moved 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 take on water.