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Lab Exercise 3 (Two Parts):Part 1: Determining Osmotic Concentration and TonicityPart 2: Determining the Osmotic Concentration, Tonicity, and the Relative Effects ofDifferent Solutions on Living Cells Virtual LabReview the concept of osmosis in your textbook (Silverthorn 8thed p124-130; 7thed p125-132) & Solutions (Silverthorn 8th& 7thed p42-43 or Figure 2.7), prior to coming to lab.Activities:1.Complete the Lab Exercise 3 packetComplete all the sections including data fields that are within the lab packet. They are in red font.Watch the 3 videos as indicated in the lab.Complete the post-lab questions at the end of the lab.2.Complete PhysioEX Exercise 1 Activity 3 Simulating Osmotic PressureThis activity will be demonstrated by the Instructor in the pre-lab introduction video. (Don’t worry if you don’t have PhsyioEx).3.Upload finished packet through assignment link for grading.Objectives:Part 1:1.Understand and apply the following terminology: osmotic concentration, osmoticpressure, osmotic equilibrium; penetrating solute (PS), non-penetrating solute (NPS)2.When comparing 2 solutions separated by a semi-permeable membrane, be able toindicate their tonicity: hypertonic, hypotonic, isotonic 3.Apply your knowledge of osmosis and tonicity in physiological situations 4.Calculate osmotic concentration if given molar concentrations and the characteristics ofthe solute molecules involved 5.When comparing 2 solutions, be able to indicate their relative osmotic concentration(hypo, iso or hyper-osmotic);6.Design a simple experiment that would test a given hypothesis related to osmosis anddiffusion. Employ the steps to the scientific method in the experimental protocol. Part 2:7.Observechanges that occur in living cells and be able to predict how the cell volume willchange when placed into solutions of varying osmotic concentrations with variable tonicity. 8.Be able to use proper terminology to describe tonicity and osmotic concentration when comparing two solutions. 9.Employ the scientific method to test the following hypothesis: A living cell placed into asolution that is isotonic and hyperosmotic will not exhibit a netchange in volume as measured by size when observed over time. Key Terms: Osmosis, selective permeability, hypertonic, hypotonic, isotonic, ICF, ISF, equilibrium, osmotic pressure, molarity, osmolality, ionic bonds, covalent bonds, hyperosmotic, hypoosmotic, isosmotic, hemolysis, osmometer, PS, NPS, crenation.Mitchem, F2020, page 1/13
Part 1: Determining Osmotic Concentration and TonicityIn last week’s experiment (Lab Exercise 2, Part 3) you demonstrated the processes of dialysisand osmosis across a non-living, semi-permeable membrane. You could tell that osmosisoccurred because your dialysis bag gained weight. Osmosis is the net diffusion of water acrossa membrane. For osmosis to occur, the membrane must be 1) permeable to water, but 2)impermeable to some or all of the solutes; therefore, the membrane is considered semi-permeable(in living cells the term selectively permeableis used). When you have a