Membranes: Cell Membrane and Purple Dark

Cell Membranes and Transport Hands-On Labs, Inc. Version 42-0033-00-01 Lab draw Assistant This document is not meant to be a substitute for a formal laboratoryoratory report. The Lab Report Assistant is simply a summary of the investigates questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students writing of lab reports by providing this information in an editable file which can be s fetch up to an instructor. Exercise 1 Diffusion ObservationsData Table 1 Rate of distribution in dissimilar temperatures ? C Minutes Temperature InitialTemp. InitialColor 5 10 15 20 25 30 60 Cold 3 black-and-blue uninfected white white white white white by and hulking white some blue Ambient 25 white gamey Light blue gallant blue color blue purple purple purple Dark purple Hot 96 white purple DARKpurpleple Dark purple Dark purple Dark purple Dark purple Dark purple Questions A. Write a one-paragraph compend of the re sults for the procedure. Provide reasons for the difference in the rate of diffusion at the unalike temperatures.The results of this lab were greatly influenced by the temperature of the KI solution. The bag keyd in the heated solution began to change color (from white to light purple) to the highest degree immediately and changed to dark purple within 7minutes. The second bag in room temp. solution took active 5 minutes to see a slight change in color (from white to light blue) and nearly 20 to turn dark purple. The third bag in the raw temp. solution barely changed color at all at the end of the hour (bluish tint. ) According to the text (p. 68), Be manage the driving force for diffusion is the kinetic energy of the olecules themselves. The speed of diffusion is influenced by molecular size ( the smaller, the faster) and by temperature ( the warmer, the faster). Through this lab experiment we were able to see that diffusion did supervene faster in the warm piddle by see ing the double-quick change in color of the contents inside the baggie. B. Did the sizes of the molecules affect their campaign? Yes, the smaller the molecules (KI) were able to permeate thru the bag where as the bigger molecules ( weewee) and give start could not permeate thru the membrane bag due to their large size. C.Give an example of diffusion between a solid and a eloquent a gas and a liquid between two different solids. (solid/solid) Gold and lead- over time, molecules of lead ordain diffuse into the gold and wickedness versa. (solid/liquid) Sugar and water- Sugar will dissolve in water. (Gas/liquid)Perfume and air- the scent will spread. Exercise 2 Osmosis Observations DataTable 2 Potato stack Contents in TestTube Initial Mass of two Potato Strips Final Mass of Two Strips MassDifference % Change inMass Class Average Percent Change in Mass (if available) a) Distilled Water 3. g 5g 1. 4 38% b) 1. 0 M sucrose 3. 4g 2. 1g -1. 3 -38% c) 0. 8 M Sucrose 3. 6g 2. 1g -1. 5 42% d) 0. 6 M Sucrose 3. 5g 2. 6g -. 9 -25% e) 0. 4 M Sucrose 3. 5g 3g -. 5 -14% f) 0. 2 M Sucrose 3. 4g 3. 7g . 3 9% Questions A. Describe how the white potato cylinders changed in their turgidity. Identify which of the solutions were isotonic, hypertonic, and hypotonic in relation to the potato. a) Distilled Water No change in turgidity. hypotonic solution. b) 1. 0 M Sucrose precise turgid. hypertonic solution. ) 0. 8 M Sucrose Turgid. Hypertonic solution. d) 0. 6 M Sucrose Moderately turgid. Hypertonic solution. e) 0. 4 M Sucrose Slighty turgid. Hypertonic solution. f) 0. 2 M Sucrose No change in turgidity. Hypotonic solution. B. What would happen to a red blood cell placed in distilled water? Why? Distilled water is a hypotonic solution which essence in contains no solutes. According to the text (p. 72), Cells placed in a hypotonic solution plump up rapidly as water rushes into them. This means that a RBC would eventually pop. C.Create a graph of your experiment al data by plotting the percent change in potato atomic pile against sucrose poor boyity. Label the x-axis as Molarity of Sucrose, and the y-axis as % Change in Mass. D. Determine the molar concentration of the sucrose contained in the potato strips by using the graph created in question C. At the point where the molar concentration of the sucrose in the potato would be isotonic to the sucrose, thither would be no net change in the potato mass. On the graph, this is located at the 0% change. Draw a line from this place on the y-axis to intersect the line.From the line draw a line drop to the x-axis to find the molarity. Molar concentration of sucrose in potato = . 3 M Exercise 3 The Effect of Solvents on Membrane remains Observations Data Table 3 Color Intensity from Damaged beetroot Cells TestTube Solution Treatment ColorIntensity0 10 Condition of Beet (turgid, flaccid, etc. ) a 70% Isopropyl intoxicant 10 Very flacid b 35% Isopropyl alcohol 7 bendable c 17. 5% Isopropyl alc ohol 3 little firm d Distilled Water 0 Very firm. Questions A. What is the reasoning nooky the use of egg whites?How does this part of the experiment relate to membranes? Egg whites would put up a lipid layer mimicking the cell membrane layer of a cell. Also egg white are largely composed of water this would also mimic the cell membrane. B. What do the results of test tube e tell about the effect of isopropyl alcohol on egg whites? The effects of the alcohol on the on the egg whites were that it made the chunky as almost if they had been cooked. C. What do the results of test tube f tell about the effect of isopropyl alcohol on oil?How does this relate to membranes? The oil sinks in relation to the alcohol. This is related to membranes due to the hydrophilic and hydrophobic aspects. Lipids arrange so that the hydrophobic tail regions are isolated from the surrounding polar fluid, cause the more hydrophilic head regions to associate with the intracellular (cytosolic) and extrac ellular faces of the resulting bilayer. D. establish on the results from test tubes a through d, which of the solutions caused the most damage on the membrane system? Explain your answer.The solution with the highest concentration of Isopropyl alcohol cause the most damage to the membrane because exposure to high concentration of total solvents would disrupt membrane integrity. E. Using the same data collection method, learn a hypothesis and use the scientific method to design an experiment that would show the effect of temperature stress on membranes. Extreme temperatures, mainly -5? C and 70? C, will significantly damage the cell membrane term the temperatures closer to room temperature will cause only slight damage, if any.